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Contains fulltext : 219574.pdf (Publisher’s version ) (Open Access) This study examined whether teachers' perceptions of students' behavior (referring to halo effects) and the behavior of teacher-perceived friends (referring to association effects) influenced teachers' ability to recognize students identified as bullies, victims, and prosocial by their peers. Data came from 1,458 children (M age = 10.5, 47.5% girls) and 56 teachers (M age = 41.4, 63.5% females). Perceived likeability was associated with decreased odds and teachers' perceptions of popularity and externalizing behavior were associated with increased odds for teacher attunement to bullying. Perceived likeability and affiliation were associated with decreased odds for teacher attunement to victimized students. Teachers' perceptions of externalizing behavior were associated with decreased odds, whereas teachers' perceptions of affiliation and academic competence were associated with increased odds for attunement to prosociality. Finally, a positive association was found between teacher attunement and the average behavior of teacher-perceived friends for bullying, victimization, and prosociality. 18 p.

Impulse control disorders (ICDs) are characterized by generalized difficulty controlling emotions and behaviors. ICDs are a broad group of the central nervous system (CNS) disorders including conduct disorder, intermittent explosive, oppositional-defiant disorder, antisocial personality disorder, kleptomania, pyromania and other illnesses. Although they all share a common feature (aberrant impulsivity), their pathobiology is complex and poorly understood. There are also currently no ICD-specific therapies to treat these illnesses. Animal models are a valuable tool for studying ICD pathobiology and potential therapies. The zebrafish (Danio rerio) has become a useful model organism to study CNS disorders due to high genetic and physiological homology to mammals, and sensitivity to various pharmacological and genetic manipulations. Here, we summarize experimental models of impulsivity and ICD in zebrafish and highlight their growing translational significance. We also emphasize the need for further development of zebrafish ICD models to improve our understanding of their pathogenesis and to search for novel therapeutic treatments.

Background Non-pharmacological interventions are recommended for the treatment of challenging behaviours in individuals with intellectual disabilities by clinical guidelines. However, evidence for their effectiveness is ambiguous. The aim of the current meta-analysis is to update the existing evidence, to investigate long-term outcome, and to examine whether intervention type, delivery mode, and study design were associated with differences in effectiveness. Method An electronic search was conducted using the databases Medline, Eric, PsychINFO and Cinahl. Studies with experimental or quasi-experimental designs were included. We performed an overall random-effect meta-analysis and subgroup analyses. Results We found a significant moderate overall effect of non-pharmacological interventions on challenging behaviours (d = 0.573, 95% CI [0.352-0.795]), and this effect appears to be longlasting. Interventions combining mindfulness and behavioural techniques showed to be more effective than other interventions. However, this result should be interpreted with care due to possible overestimation of the subgroup analysis. No differences in effectiveness were found across assessment times, delivery modes or study designs. Conclusions Non-pharmacological interventions appear to be moderately effective on the short and long term in reducing challenging behaviours in adults with intellectual disabilities.

Background Non‐pharmacological interventions are recommended for the treatment of challenging behaviours in individuals with intellectual disabilities by clinical guidelines. However, evidence for their effectiveness is ambiguous. The aim of the current meta‐analysis is to update the existing evidence, to investigate long‐term outcome, and to examine whether intervention type, delivery mode, and study design were associated with differences in effectiveness. Method An electronic search was conducted using the databases Medline, Eric, PsychINFO and Cinahl. Studies with experimental or quasi‐experimental designs were included. We performed an overall random‐effect meta‐analysis and subgroup analyses. Results We found a significant moderate overall effect of non‐pharmacological interventions on challenging behaviours (d = 0.573, 95% CI [0.352–0.795]), and this effect appears to be longlasting. Interventions combining mindfulness and behavioural techniques showed to be more effective than other interventions. However, this result should be interpreted with care due to possible overestimation of the subgroup analysis. No differences in effectiveness were found across assessment times, delivery modes or study designs. Conclusions Non‐pharmacological interventions appear to be moderately effective on the short and long term in reducing challenging behaviours in adults with intellectual disabilities.

Male house mice excrete large amounts of protein in their urinary scent marks, mainly composed of Major Urinary Proteins (MUPs), and these lipocalins function as pheromones and pheromone carriers. Here, we review studies on sexually dimorphic MUP expression in house mice, including the proximate mechanisms controlling MUP gene expression and their adaptive functions. Males excrete 2 to 8 times more urinary protein than females, though there is enormous variation in gene expression across loci in both sexes. MUP expression is dynamically regulated depending upon a variety of factors. Males regulate MUP expression according to social status, whereas females do not, and males regulate expression depending upon health and condition. Male-biased MUP expression is regulated by pituitary secretion of growth hormone (GH), which binds receptors in the liver, activating the JAK2-STAT5 signaling pathway, chromatin accessibility, and MUP gene transcription. Pulsatile male GH secretion is feminized by several factors, including caloric restriction, microbiota depletion, and aging, which helps explain condition-dependent MUP expression. If MUP production has sex-specific fitness optima, then this should generate sexual antagonism over allelic expression (intra-locus sexual conflict) selectively favoring sexually dimorphic expression. MUPs influence the sexual attractiveness of male urinary odor and increased urinary protein excretion is correlated with the reproductive success of males but not females. This finding could explain the selective maintenance of sexually dimorphic MUP expression. Producing MUPs entails energetic costs, but increased excretion may reduce the net energetic costs and predation risks from male scent marking as well as prolong the release of chemical signals. MUPs may also provide physiological benefits, including regulating metabolic rate and toxin removal, which may have sex-specific effects on survival. A phylogenetic analysis on the origins of male-biased MUP gene expression inMus musculussuggests that this sexual dimorphism evolved by increasing male MUP expression rather than reducing female expression.

The aim of this study was to evaluate the effect of 16L:8D photoperiod with green (GREEN) or white (WHITE) lights during incuba-tion on hatching performance, blood melatonin, corti-costerone, and serotonin levels, hypothalamic expressions of genes related to photoreception, seroto-nin, and stress systems in layers in relation with feather pecking behavior. Dark incubation (DARK) was the control. Eggs (n = 1,176) from Brown Nick breeders in 2 batches (n = 588/batch) were incubated in the exper-iment. A total of 396 female chicks and 261 hens were used at rearing and laying periods until 40 wk. Incuba-tion lighting did not affect hatchability, day-old chick weight, and length, but resulted in a more synchronized hatch as compared with the DARK. The effect of incu-bation lighting on blood hormones was not significant except for reduced serotonin in the GREEN group at the end of the experiment. There was no effect of incu-bation lighting on gentle, severe, and aggressive peck-ing of birds during the early rearing period. From 16 wk, GREEN hens showed increased gentle pecking with increasing age. WHITE hens had the highest gen-tle pecking frequency at 16 wk while they performed less gentle but higher severe and aggressive pecks at 24 and 32 wk. At hatching, the hypothalamic expression of CRH, 5-HTR1A, and 5-HTR1B was higher for the WHITE group compared with both GREEN and DARK, however, 5-HTT expression was higher in GREEN than WHITE which was similar to DARK. Except for the highest VA opsin expression obtained for WHITE hens at 40 wk of age, there was no change in hypothalamic expression levels of rhodopsin, VA opsin, red, and green opsins at any age. Although blood hormone levels were not consistent, results provide pre-liminary evidence that incubation lighting modulates the pecking tendencies of laying hens, probably through the observed changes in hypothalamic expres-sion of genes related to the serotonin system and stress. Significant correlations among the hypothalamic gene expression levels supplied further evidence for the asso-ciations among photoreception, serotonin, and stress systems., Ege University [16-ZRF-071, 18-ZRF-026], ACKNOWLEDGMENTS Rudie Koopmanschap from Wageningen University is acknowledged for the analysis of whole-blood serotonin levels. This study was funded by Ege University (grant numbers: 16-ZRF-071, and 18-ZRF-026) .

Objectives: To systematically review literature on efficacy of amantadine on behavior (irritability/aggression/agitation, emotional lability, apathy, impairment of executive functioning), participation, quality-of-life (QoL), and safety, in patients with acquired brain injury (ABI). Amantadine is widely used clinically, so comprehensive information on efficacy, participation, QoL and safety is relevant. Methods: We used PRISMA Guidelines. We searched PubMed/EMBASE/CINAHL (last search 28-8-2018) Two independent reviewers performed selection and data-extraction. Quality of studies was assessed, using CONSORT and Quality Assessment Tool for Quantitative Studies (QATFQS). Results: Eleven out of 500 studies were included. Of five RCTs, two reported significant effects on irritability/aggression, and one no effect. One RCT on cognition no effect. One prospective cohort study showed a significant effect on executive functioning. One retrospective study was inconclusive. One single-case experimental design (SCED) study reported significant effect on apathy and three case-reports indicated effects on behavior. QoL and societal participation were not measured. No safety issues emerged. Conclusion: Amantadine may be efficacious on irritability and aggression after ABI. Amantadine is a safe drug in the presence of adequate creatinine clearance. Future studies should use designs, suitable for the heterogeneous ABI population, like randomized SCEDs, and should include the effect on societal participation and QoL.

The ABC method is a behaviour management technique for use by nurses. ABC refers to the identification of Antecedent events, target Behaviours, and Consequent events. In this longitudinal intervention study with double baseline measurements we evaluated the effectiveness of the ABC method in patients with behavioural problems after acquired brain injury. Fifty-six patients participated in this study. Outcome was measured in terms of overall neuropsychiatric problem behaviour, aggression, apathy and emotional burden experienced by nurses. A process evaluation was performed to investigate usability and acceptability of the method and identify factors that influenced effectiveness. Friedman's ANOVA showed a small significant reduction over time in overall neuropsychiatric problem behaviour and aggression. The reduction was most prominent between the first baseline measurement and the post-implementation and follow-up measurements, not between the second baseline measurement and the post-implementation or follow-up measurements. This first group study on the effects of the ABC method could not prove this technique is effective for patients with behavioural problems after acquired brain injury. Nurses indicated that the ABC method was not fully implemented in their daily routines. This may have influenced results and makes it yet premature to draw firm conclusions on the effects of the ABC method.

Introduction Experimental models of neuropsychiatric disorders, for example, ADHD, are used to mimic specific phenotypic traits of a complex human disorder. However, it remains unresolved to what extent the animal phenotype reflects the specific human trait. The null mutant mouse of the serotonin‐synthesizing tryptophan hydroxylase‐2 (Tph2 ‐/‐) gene has been proposed as experimental model for ADHD with high face validity for impulsive, aggressive, and anxious behaviors. To validate this ADHD‐like model, we examined the Tph2‐/‐ phenotype in humans when considering allelic variation of TPH2 function (“reverse phenotyping”). Methods 58 participants (6 females, 8–18 years) were examined, of whom 32 were diagnosed with ADHD. All participants were phenotyped for impulsivity, aggression, and anxiety using questionnaires, behavioral tests, and MRI scanning while performing the 4‐choice serial reaction time task. Additionally, participants were genotyped for the TPH2 G‐703T (rs4570625) polymorphism. To analyze the relation between TPH2 G‐703T variants and the impulsive/aggressive/anxious phenotype, mediation analyses were performed using behavioral and MRI data as potential mediators. Results We found that the relation between TPH2 G‐703T and aggression as part of the reverse Tph2‐/‐ phenotype was mediated by structure and function of the right middle and inferior frontal gyrus. Conclusion At the example of trait aggression, our results support the assumption that the Tph2 null mutant mouse reflects the TPH2 G‐703T‐dependent phenotype in humans. Additionally, we conclude that “reverse phenotyping” is a promising method to validate experimental models and human findings for refined analysis of disease mechanisms., The Tph2‐/‐ mouse has been proposed as an experimental model for ADHD. Translation of an animal phenotype into humans to examine its face validity (reverse phenotyping). Phenotyping included impulsivity, aggression, and anxiety, reflecting comorbid conditions of ADHD. Use of the RDoC approach to address phenotype dimensions in an isolated manner.

Background: Little is known about how the workforce influences quality in long term care facilities for older people. Staff numbers are important but do not fully explain this relationship.Objectives: To develop theoretical explanations for the relationship between long-term care facility staffing and quality of care as experienced by residents. Design: A realist evidence synthesis to understand staff behaviours that promote quality of care for older people living in long-term care facilities. Setting: Long-term residential care facilitiesParticipants: Long-term care facility staff, residents, and relatives Methods: The realist review, (i) was co-developed with stakeholders to determine initial programme the-ories, (ii) systematically searched the evidence to test and develop theoretical propositions, and (iii) vali-dated and refined emergent theory with stakeholder groups.Results: 66 research papers were included in the review. Three key findings explain the relationship be-tween staffing and quality: (i) quality is influenced by staff behaviours; (ii) behaviours are contingent on relationships nurtured by long-term care facility environment and culture; and (iii) leadership has an im-portant influence on how organisational resources (sufficient staff effectively deployed, with the knowl-edge, expertise and skills required to meet residents' needs) are used to generate and sustain quality-promoting relationships. Six theoretical propositions explain these findings.Conclusion: Leaders (at all levels) through their role-modelling behaviours can use organisational re-sources to endorse and encourage relationships (at all levels) between staff, residents, co-workers and family (relationship centred care) that constitute learning opportunities for staff, and encourage quality as experienced by residents and families.Crown Copyright (c) 2021 Published by Elsevier Ltd. All rights reserved.

Objective: APOE status has been associated to affective symptoms in cognitively impaired subjects, with conflicting results.Methods: Databases CINAHL, Embase, PsychINFO and PubMed were searched for studies evaluating APOE genotype with affective symptoms in MCI and AD dementia. Symptoms were meta-analyzed separately and possible sources of heterogeneity were examined.Results: Fifty-three abstracts fulfilled the eligibility criteria. No association was found between the individual symptoms and APOE epsilon 4 carriership or zygosity. For depression and anxiety, only pooled unadjusted estimates showed positive associations with between-study heterogeneity, which could be explained by variation in study design, setting and way of symptom assessment.Conclusions: There is no evidence that APOE epsilon 4 carriership or zygosity is associated with the presence of depression, anxiety, apathy, agitation, irritability or sleep disturbances in cognitively impaired subjects. Future research should shift its focus from this single polymorphism to a more integrated view of other biological factors.

Glial cell line-derived neurotrophic factor (GDNF) promotes the survival of dopaminergic neurons in vitro and in vivo. For this reason, GDNF is currently in clinical trials for the treatment of Parkinson’s disease (PD). However, how endogenous GDNF influences dopamine system function and animal behavior is not fully understood. We recently generated GDNF hypermorphic mice that express increased levels of endogenous GDNF from the native locus, resulting in augmented function of the nigrostriatal dopamine system. Specifically, Gdnf wt/hyper mice have a mild increase in striatal and midbrain dopamine levels, increased dopamine transporter activity, and 15% increased numbers of midbrain dopamine neurons and striatal dopaminergic varicosities. Since changes in the dopamine system are implicated in several neuropsychiatric diseases, including schizophrenia, attention deficit hyperactivity disorder (ADHD) and depression, and ectopic GDNF delivery associates with side-effects in PD models and clinical trials, we further investigated Gdnf wt/hyper mice using 20 behavioral tests. Despite increased dopamine levels, dopamine release and dopamine transporter activity, there were no differences in psychiatric disease related phenotypes. However, compared to controls, male Gdnf wt/hyper mice performed better in tests measuring motor function. Therefore, a modest elevation of endogenous GDNF levels improves motor function but does not induce adverse behavioral outcomes.

Background: Cross-sectional studies report relations between externalizing behavior and structural abnormalities in cortical thickness of prefrontal regions and volume reductions in subcortical regions. To understand how these associations emerge and develop, longitudinal designs are pivotal. Method: In the current longitudinal study, a community sample of children, adolescents and young adults (N = 271) underwent magnetic resonance imaging (MRI) in three biennial waves (680 scans). At each wave, aspects of externalizing behavior were assessed with parent-reported aggression and rule-breaking scores (Child Behavior Checklist), and self-reported aggression scores (Buss-Perry Aggression Questionnaire). Regions of interest (ROIs) were selected based on prior research: dorsolateral prefrontal (dlPFC), orbitofrontal (OFC), anterior cingulate cortex (ACC), insula, and parahippocampal cortex, as well as subcortical regions. Linear mixed models were used to assess the longitudinal relation between externalizing behavior and structural brain development. Structural covariance analyses were employed to identify whether longitudinal relations between ROIs (maturational coupling) were associated with externalizing behavior. Results: Linear mixed model analyses showed a negative relation between parent-reported aggression and right hippocampal volume. Moreover, this longitudinal relation was driven by change in hippocampal volume and not initial volume of hippocampus at time point 1. Exploratory analyses showed that stronger maturational coupling between prefrontal regions, the limbic system, and striatum was associated with both low and high externalizing behavior. Conclusions: Together, these findings reinforce the hypothesis that altered structural brain development coincides with development of more externalizing behavior. These findings may guide future research on normative and deviant development of externalizing behavior.

Research suggests that restrictive measures are widely used on adolescents with mild intellectual disabilities. In the Netherlands, restrictive measures are defined as all measures that limit the freedom of a person. In most countries, legislation and policies that seek to reduce the use of restrictive measures focus on seclusion and mechanical and physical restraints. The study aimed to investigate the extent to which restrictive practices are used in the care of adolescents with mild intellectual disabilities while also exploring the attitudes of support staff toward these interventions. A survey study was done among a nationally representative Dutch research sample consisting of support staff. A structured questionnaire was completed by 195 staff members (response of 68.7%) working in settings providing care for people with intellectual disabilities. The measures generally used by staff members who work with adolescents with mild intellectual disabilities involved restricting the freedom of movement and so‐called social restrictions (such as limiting the use of mobile phones). Nearly all respondents considered restrictive measures to be justified in the case of danger, physical aggression, or sexually abusive behavior (87.8–96.8%). Frequently mentioned reasons for using restrictive measures were averting or avoiding danger (90.4 and 83.0%, respectively) and calming the adolescent (63.8%). Although seclusion and mechanical and physical restraints were generally considered most intrusive, staff members were aware that social restrictions could also be instrusive. The fact that current policies do not address these measures makes support staff question the lawfulness of their actions. As well as staff training to reduce the use of restrictive measures, rules, and legislation are also needed to clarify the options and limits to using such measures in the professional care of adolescents with mild intellectual disabilities.

Research suggests that restrictive measures are widely used on adolescents with mild intellectual disabilities. In the Netherlands, restrictive measures are defined as all measures that limit the freedom of a person. In most countries, legislation and policies that seek to reduce the use of restrictive measures focus on seclusion and mechanical and physical restraints. The study aimed to investigate the extent to which restrictive practices are used in the care of adolescents with mild intellectual disabilities while also exploring the attitudes of support staff toward these interventions. A survey study was done among a nationally representative Dutch research sample consisting of support staff. A structured questionnaire was completed by 195 staff members (response of 68.7%) working in settings providing care for people with intellectual disabilities. The measures generally used by staff members who work with adolescents with mild intellectual disabilities involved restricting the freedom of movement and so‐called social restrictions (such as limiting the use of mobile phones). Nearly all respondents considered restrictive measures to be justified in the case of danger, physical aggression, or sexually abusive behavior (87.8–96.8%). Frequently mentioned reasons for using restrictive measures were averting or avoiding danger (90.4 and 83.0%, respectively) and calming the adolescent (63.8%). Although seclusion and mechanical and physical restraints were generally considered most intrusive, staff members were aware that social restrictions could also be instrusive. The fact that current policies do not address these measures makes support staff question the lawfulness of their actions. As well as staff training to reduce the use of restrictive measures, rules, and legislation are also needed to clarify the options and limits to using such measures in the professional care of adolescents with mild intellectual disabilities.

Australoheros facetus is a neotropical cichlid and an exotic species in the Guadiana and Odelouca basins (Southern Portugal). In this research, we aimed to characterize the main behavioural patterns and circulating hormones, 17 beta-estradiol (E-2) for females, and testosterone, 11-ketotestosterone (11KT) and cortisol for both sexes, during the formation of social groups, a crucial step in the life-history of A. facetus. A pair-breeding strategy with territorial behaviour and aggressive interactions was found, with a positive correlation between dominance and size for both sexes. There were no significant differences between non-territorial and territorial individuals in the baseline levels of hormones, but 11KT was higher in males when they became territorial, as E-2 for territorial females, while there was no clear pattern for testosterone. In contrast, cortisol was higher in non-territorial males and correlated negatively with social dominance. These results suggest that size is the main driver for social dominance and that formation of stable hierarchies result in higher circulating 11KT and lowers stress in territorial males. Related to A. facetus' behaviour, aggressiveness and biparental care may be an advantage during the invasion process of A. facetus, facilitating colonization of new habitats. National Council for Technological and Scientific Development of Brazil (CNPq), Program Science without Borders [245971/20122] FCT-Foundation for Science and Technology [UID/Multi/04326/2013, SFRH/BPD/67008/2009] info:eu-repo/semantics/publishedVersion

Converging evidence suggests a role of serotonin (5-hydroxytryptamine, 5-HT) and tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme of 5-HT synthesis in the brain, in modulating long-term, neurobiological effects of early-life adversity. Here, we aimed at further elucidating the molecular mechanisms underlying this interaction, and its consequences for socio-emotional behaviors, with a focus on anxiety and social interaction. In this study, adult, male Tph2 null mutant (Tph2(-/-)) and heterozygous (Tph2(+/-)) mice, and their wildtype littermates (Tph2(+/+)) were exposed to neonatal, maternal separation (MS) and screened for behavioral changes, followed by genome-wide RNA expression and DNA methylation profiling. In Tph2(-/-) mice, brain 5-HT deficiency profoundly affected socio-emotional behaviors, i.e., decreased avoidance of the aversive open arms in the elevated plus-maze (EPM) as well as decreased prosocial and increased rule breaking behavior in the resident-intruder test when compared to their wildtype littermates. Tph2(+/-) mice showed an ambiguous profile with context-dependent, behavioral responses. In the EPM they showed similar avoidance of the open arm but decreased prosocial and increased rule breaking behavior in the resident-intruder test when compared to their wildtype littermates. Notably, MS effects on behavior were subtle and depended on the Tph2 genotype, in particular increasing the observed avoidance of EPM open arms in wildtype and Tph2(+/-) mice when compared to their Tph2(-/-) littermates. On the genomic level, the interaction of Tph2 genotype with MS differentially affected the expression of numerous genes, of which a subset showed an overlap with DNA methylation profiles at corresponding loci. Remarkably, changes in methylation nearby and expression of the gene encoding cholecystokinin, which were inversely correlated to each other, were associated with variations in anxiety-related phenotypes. In conclusion, next to various behavioral alterations, we identified gene expression and DNA methylation profiles to be associated with TPH2 inactivation and its interaction with MS, suggesting a gene-by-environment interaction-dependent, modulatory function of brain 5-HT availability.

Converging evidence suggests a role of serotonin (5-hydroxytryptamine, 5-HT) and tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme of 5-HT synthesis in the brain, in modulating long-term, neurobiological effects of early-life adversity. Here, we aimed at further elucidating the molecular mechanisms underlying this interaction, and its consequences for socio-emotional behaviors, with a focus on anxiety and social interaction. In this study, adult, male Tph2 null mutant (Tph2(-/-)) and heterozygous (Tph2(+/-)) mice, and their wildtype littermates (Tph2(+/+)) were exposed to neonatal, maternal separation (MS) and screened for behavioral changes, followed by genome-wide RNA expression and DNA methylation profiling. In Tph2(-/-) mice, brain 5-HT deficiency profoundly affected socio-emotional behaviors, i.e., decreased avoidance of the aversive open arms in the elevated plus-maze (EPM) as well as decreased prosocial and increased rule breaking behavior in the resident-intruder test when compared to their wildtype littermates. Tph2(+/-) mice showed an ambiguous profile with context-dependent, behavioral responses. In the EPM they showed similar avoidance of the open arm but decreased prosocial and increased rule breaking behavior in the resident-intruder test when compared to their wildtype littermates. Notably, MS effects on behavior were subtle and depended on the Tph2 genotype, in particular increasing the observed avoidance of EPM open arms in wildtype and Tph2(+/-) mice when compared to their Tph2(-/-) littermates. On the genomic level, the interaction of Tph2 genotype with MS differentially affected the expression of numerous genes, of which a subset showed an overlap with DNA methylation profiles at corresponding loci. Remarkably, changes in methylation nearby and expression of the gene encoding cholecystokinin, which were inversely correlated to each other, were associated with variations in anxiety-related phenotypes. In conclusion, next to various behavioral alterations, we identified gene expression and DNA methylation profiles to be associated with TPH2 inactivation and its interaction with MS, suggesting a gene-by-environment interaction-dependent, modulatory function of brain 5-HT availability.

Converging evidence suggests a role of serotonin (5-hydroxytryptamine, 5-HT) and tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme of 5-HT synthesis in the brain, in modulating long-term, neurobiological effects of early-life adversity. Here, we aimed at further elucidating the molecular mechanisms underlying this interaction, and its consequences for socio-emotional behaviors, with a focus on anxiety and social interaction. In this study, adult, male Tph2 null mutant (Tph2\(^{-/-}\)) and heterozygous (Tph2\(^{+/-}\)) mice, and their wildtype littermates (Tph2\(^{+/+}\)) were exposed to neonatal, maternal separation (MS) and screened for behavioral changes, followed by genome-wide RNA expression and DNA methylation profiling. In Tph2\(^{-/-}\) mice, brain 5-HT deficiency profoundly affected socio-emotional behaviors, i.e., decreased avoidance of the aversive open arms in the elevated plus-maze (EPM) as well as decreased prosocial and increased rule breaking behavior in the resident-intruder test when compared to their wildtype littermates. Tph2\(^{+/-}\) mice showed an ambiguous profile with context-dependent, behavioral responses. In the EPM they showed similar avoidance of the open arm but decreased prosocial and increased rule breaking behavior in the resident-intruder test when compared to their wildtype littermates. Notably, MS effects on behavior were subtle and depended on the Tph2 genotype, in particular increasing the observed avoidance of EPM open arms in wildtype and Tph2\(^{+/-}\) mice when compared to their Tph2\(^{-/-}\) littermates. On the genomic level, the interaction of Tph2 genotype with MS differentially affected the expression of numerous genes, of which a subset showed an overlap with DNA methylation profiles at corresponding loci. Remarkably, changes in methylation nearby and expression of the gene encoding cholecystokinin, which were inversely correlated to each other, were associated with variations in anxiety-related phenotypes. In conclusion, next to various behavioral alterations, we identified gene expression and DNA methylation profiles to be associated with TPH2 inactivation and its interaction with MS, suggesting a gene-by-environment interaction-dependent, modulatory function of brain 5-HT availability.

Executive function and intelligence are negatively associated with aggression, yet the role of executive function has rarely been examined in the context of school bullying. We studied whether different domains of executive function and non-verbal intelligence are associated with bullying involvement in early elementary school. The association was examined in a population-based sample of 1,377 children. At age 4 years we assessed problems in inhibition, shifting, emotional control, working memory and planning/organization, using a validated parental questionnaire (the BRIEF-P). Additionally, we determined child non-verbal IQ at age 6 years. Bullying involvement as a bully, victim or a bully-victim in grades 1-2 of elementary school (mean age 7.7 years) was measured using a peer-nomination procedure. Individual bullying scores were based on the ratings by multiple peers (on average 20 classmates). Analyses were adjusted for various child and maternal socio-demographic and psychosocial covariates. Child score for inhibition problems was associated with the risk of being a bully (OR per SD = 1.35, 95%CI: 1.09-1.66), victim (OR per SD = 1.21, 95%CI: 1.00-1.45) and a bully-victim (OR per SD = 1.55, 95%CI: 1.10-2.17). Children with higher non-verbal IQ were less likely to be victims (OR = 0.99, 95%CI: 0.98-1.00) and bully-victims (OR = 95%CI: 0.93-0.98, respectively). In conclusion, our study showed that peer interactions may be to some extent influenced by children's executive function and non-verbal intelligence. Future studies should examine whether training executive function skills can reduce bullying involvement and improve the quality of peer relationships.

The purpose of the present study was to develop a new assessment procedure of social information processing (SIP) for adolescents, to explore its validity and to examine whether it differentiated between IQ groups. Ninety-four adolescents within secure residential care were administered the SIP instrument, the Youth Self Report and two subtests of the WISC/WAIS. Results showed that the constructs underlying the items of the instrument were associated with profiles from the SIP theory, the subsequent SIP steps were correlated, and several SIP steps were correlated to self-reported behavior. No differences were found between IQ groups. These first results have implications for adjustment of the instrument. Further research should confirm construct validity and psychometric qualities of the scales.Keywords: Social information processing (SIP), Mild to borderline intellectual disability (MBID), Assessment, Validity, Adolescents, Residential care

Intensively reared piglets may face many early life challenges and these may affect behavior. The objective of this study was to examine the relationship between piglets’ early life circumstances and their behavioral response in a backtest. Hereto, 992 piglets of 14 d of age were subjected to a backtest, in which they were 1 min restrained in supine position. The number of struggles in the backtest was assessed in relation to data on ADG, BW, BW relative to litter mates, teat order, litter size, and health. Piglets that had a lower ADG from birth till the test day were struggling more (b = -2.4 g ADG/struggle; P = 0.03). Also piglets with a lower BW at 14 d of age tended to respond more actively in the backtest (b = -0.03 kg/struggle; P = 0.08). The response to the backtest was unrelated to ADG from birth till weaning, birth weight, weaning weight, teat order, litter size, and health. ADG and BW were unrelated to the variation of backtest responses within the litter. The weak though significant relationship suggest that smaller slower growing piglets more actively respond to a challenge, either because piglets born with such a behavioral response were better able to survive, or because piglets adapted their behavioral response to their physical condition.

As sexual selection is a coevolutionary process between males and females, various morphological and behavioral traits have evolved in each sex. In the tetranychid mites Tetranychus urticae Koch and T. kanzawai Kishida (Acari: Tetranychidae), males can mate repeatedly, whereas females normally accept only the first copulation for fertilization. Since early times, it had been reported that males engage in precopulatory mate guarding and combat against conspecifics for females to enhance their reproductive success. On the other hand, it was believed that females do not have opportunities to choose their mates. In the last 10 or so years, however, several new findings related to mating behavior were reported. Some of the findings reinforce our established knowledge, whereas some of them explode it. Here, I review the mating behavior of T. urticae and T. kanzawai by incorporating recent findings and then propose a new direction for future research.

Background: Patient and visitor violence (PVV) is the most dangerous occupational hazard that health professionals must contend with. Staff training is recommended to prevent and manage PVV. There is minimal research focusing on risk factors associated with PVV in general hospital settings. Therefore, staff training is mostly based upon expert knowledge and knowledge from psychiatric and emergency settings.Objectives: This study investigates health professionals' experiences with PVV in order to describe risk factors related to PVV that occur in general hospital settings.Design: A retrospective cross-sectional survey was conducted in 2007.Setting: A university general hospital in Switzerland.Participants: 2495 out of 4845 health professionals participated (58.0% nurses & midwives, 19.2% medical doctors, 3.6% physical therapists, occupational therapists & nutritionists, 6.1% ward secretaries, medical & radiology assistants, 6.3% nursing assistants or less qualified nursing staff and 5.1% other staff). All had direct patient contact and 82% were female.Methods: Data were collected via questionnaires using the Survey of Violence Experienced by Staff German-Version-Revised, the German version of the shortened Perception of Aggression Scale and the Perception of Importance of Intervention Skills Scale. Descriptive statistics and multiple logistic regression analyses were used.Results: Risk factors associated with PVV depend upon the form of violence. Those trained in aggression management and/or those who work predominantly with patients over 65 years of age experience twice as much PVV as others. Health professionals working in emergency rooms, outpatient units, intensive care units, recovery rooms, anesthesia, intermediate care and step-down units also experience PVV more often. When health professionals are older in age, are from the medical profession, are students, or when they have an attitude rating preventive measures as being less important and aggression as emotionally letting off steam, they experience less PVV.Conclusion: Training could change the perception and the recognition of PVV, and could therefore increase the risk of experiencing PVV. The health professionals' specific occupation along with attitude and age, the patients' age, the communication and the workplace are all relevant risk factors. Further studies should investigate the impact of aggression management training and other measures that would reduce PVV. (C) 2012 Elsevier Ltd. All rights reserved.

Elevated levels of corticotropin (ACTH)-reactive immunoglobulins (ACTH IgG) were found in mates with conduct disorder, suggesting their involvement in the biology of antisocial behavior. We first aimed to confirm these findings in a large general population sample of adolescents. Secondly, we studied the association between ACTH IgG levels and hypothalamic-pituitary-adrenal (HPA) axis response to stress.Free and total ACTH IgG levels were measured in sera of 1230 adolescents (15-18 years). HPA axis activity was determined by measuring salivary cortisol before, during, and after a social stress test. Antisocial behavior was assessed using the Antisocial Behavior Questionnaire. ACTH peptide and IgG affinity kinetics for ACTH were assayed in a subsample of 90 adolescents selected for high or low ACTH IgG levels.In boys, higher total ACTH IgG levels were associated with higher antisocial behavior scores (beta = 1.05, p = 0.04), especially at high levels of free ACTH IgG. In girls, antisocial behavior was associated with low free ACTH IgG levels (beta = -0.20, p = 0.04). Stress-induced cortisol release was associated with free ACTH IgG in boys (beta(area under the curve) = -0.67, p These data show that ACTH IgG levels are related to antisocial behavior and HPA axis response to stress in adolescents. The mechanisms behind these associations, including different ACTH binding properties of IgG in subjects with antisocial behavior, deserve further attention. (C) 2013 Elsevier Ltd. All rights reserved.

Male facial width-to-height ratio (bizygomatic width scaled for face height) is a testosterone-linked trait predictive of reactive aggression, exploitative behavior, cheating, deception, and dominance. We tested whether facial width was systematically related to cause of death in a forensic sample. We hypothesized that wider-faced males, being more aggressive and robust, would be less likely than narrower-faced males to die from contact violence (stabbed, strangled, or bludgeoned to death) compared with other forms of homicide. We tested this hypothesis in a forensic data sample covering 523 male and 339 female skeletons. In these data, men with narrower faces were more likely to have died as a consequence of homicides involving direct physical contact than men with wider faces. No such effect was found for women. This effect was found when considering all causes of mortality and when limiting the sample to homicides. This finding suggests that wider-faced males are less likely to die from male–male physical violence, perhaps because of their formidability. Our findings are discussed with reference to the previous literature indicating that facial width-to-height ratio is a marker for male dominance.

Male facial width-to-height ratio (bizygomatic width scaled for face height) is a testosterone-linked trait predictive of reactive aggression, exploitative behavior, cheating, deception, and dominance. We tested whether facial width was systematically related to cause of death in a forensic sample. We hypothesized that wider-faced males, being more aggressive and robust, would be less likely than narrower-faced males to die from contact violence (stabbed, strangled, or bludgeoned to death) compared with other forms of homicide. We tested this hypothesis in a forensic data sample covering 523 male and 339 female skeletons. In these data, men with narrower faces were more likely to have died as a consequence of homicides involving direct physical contact than men with wider faces. No such effect was found for women. This effect was found when considering all causes of mortality and when limiting the sample to homicides. This finding suggests that wider-faced males are less likely to die from male–male physical violence, perhaps because of their formidability. Our findings are discussed with reference to the previous literature indicating that facial width-to-height ratio is a marker for male dominance.

Sexual selection on male coloration has been implicated in the evolution of colourful species flocks of East African cichlid fish. During adaptive radiations, animals diverge in multiple phenotypic traits, but the role of physiology has received limited attention. Here, we report how divergence in physiology may contribute to the stable coexistence of two hybridizing incipient species of cichlid fish from Lake Victoria. Males of Pundamilia nyererei (males are red) tend to defeat those of Pundamilia pundamilia (males are blue), yet the two sibling species coexist in nature. It has been suggested that red males bear a physiological cost that might offset their dominance advantage. We tested the hypothesis that the two species differ in oxidative stress levels and immune function and that this difference is correlated with differences in circulating steroid levels. We manipulated the social context and found red males experienced significantly higher oxidative stress levels than blue males, but only in a territorial context when colour and aggression are maximally expressed. Red males exhibited greater aggression levels and lower humoral immune response than blue males, but no detectable difference in steroid levels. Red males appear to trade off increased aggressiveness with physiological costs, contributing to the coexistence of the two species. Correlated divergence in colour, behaviour and physiology might be widespread in the dramatically diverse cichlid radiations in East African lakes and may play a crucial role in the remarkably rapid speciation of these fish.

Sexual selection on male coloration has been implicated in the evolution of colourful species flocks of East African cichlid fish. During adaptive radiations, animals diverge in multiple phenotypic traits, but the role of physiology has received limited attention. Here, we report how divergence in physiology may contribute to the stable coexistence of two hybridizing incipient species of cichlid fish from Lake Victoria. Males of Pundamilia nyererei (males are red) tend to defeat those of Pundamilia pundamilia (males are blue), yet the two sibling species coexist in nature. It has been suggested that red males bear a physiological cost that might offset their dominance advantage. We tested the hypothesis that the two species differ in oxidative stress levels and immune function and that this difference is correlated with differences in circulating steroid levels. We manipulated the social context and found red males experienced significantly higher oxidative stress levels than blue males, but only in a territorial context when colour and aggression are maximally expressed. Red males exhibited greater aggression levels and lower humoral immune response than blue males, but no detectable difference in steroid levels. Red males appear to trade off increased aggressiveness with physiological costs, contributing to the coexistence of the two species. Correlated divergence in colour, behaviour and physiology might be widespread in the dramatically diverse cichlid radiations in East African lakes and may play a crucial role in the remarkably rapid speciation of these fish.

We aim to stimulate an ontogenetic approach to personalities. We explain the importance of studying development for understanding proximate and ultimate aspects of personality and critically discuss, partly by perhaps provocative statements, our current lack of knowledge and potential approaches to the study of personality development. We first clarify some terminology and argue for a difference between behavioral profiles (BP; at the descriptive level) and personality ( at the explanatory level). We then focus on the issue of temporal stability of personality, arguing that based on evolutionary theory, neurophysiological knowledge, and recent findings, personality is probably less stable than often thought. Next we consider the potential influence of genes, discussing gene by environment correlations and interactions and argue that developmental changes in the regulation of DNA expression are probably more relevant than individual differences in DNA sequence. We end by suggesting perspectives for future research. (C) 2011 Wiley Periodicals, Inc. Dev Psychobiol 53: 641-655, 2011.

We aim to stimulate an ontogenetic approach to personalities. We explain the importance of studying development for understanding proximate and ultimate aspects of personality and critically discuss, partly by perhaps provocative statements, our current lack of knowledge and potential approaches to the study of personality development. We first clarify some terminology and argue for a difference between behavioral profiles (BP; at the descriptive level) and personality ( at the explanatory level). We then focus on the issue of temporal stability of personality, arguing that based on evolutionary theory, neurophysiological knowledge, and recent findings, personality is probably less stable than often thought. Next we consider the potential influence of genes, discussing gene by environment correlations and interactions and argue that developmental changes in the regulation of DNA expression are probably more relevant than individual differences in DNA sequence. We end by suggesting perspectives for future research. (C) 2011 Wiley Periodicals, Inc. Dev Psychobiol 53: 641-655, 2011.

Sexual selection on male coloration has been implicated in the evolution of colourful species flocks of East African cichlid fish. During adaptive radiations, animals diverge in multiple phenotypic traits, but the role of physiology has received limited attention. Here, we report how divergence in physiology may contribute to the stable coexistence of two hybridizing incipient species of cichlid fish from Lake Victoria. Males of Pundamilia nyererei (males are red) tend to defeat those of Pundamilia pundamilia (males are blue), yet the two sibling species coexist in nature. It has been suggested that red males bear a physiological cost that might offset their dominance advantage. We tested the hypothesis that the two species differ in oxidative stress levels and immune function and that this difference is correlated with differences in circulating steroid levels. We manipulated the social context and found red males experienced significantly higher oxidative stress levels than blue males, but only in a territorial context when colour and aggression are maximally expressed. Red males exhibited greater aggression levels and lower humoral immune response than blue males, but no detectable difference in steroid levels. Red males appear to trade off increased aggressiveness with physiological costs, contributing to the coexistence of the two species. Correlated divergence in colour, behaviour and physiology might be widespread in the dramatically diverse cichlid radiations in East African lakes and may play a crucial role in the remarkably rapid speciation of these fish.

The ecological relevance of behavioural syndromes is little studied in cooperative breeding systems where it is assumed that the behavioural type might influence individual decisions on helping and dispersal (e.g. shy, nonaggressive and nonexplorative individuals remain philopatric and helpful, whereas bold, aggressive, explorative individuals compete for vacancies outside their group and disperse). We measured the behavioural type of 19 subordinates in the cooperatively breeding cichlid fish Neolamprologus pulcher in their natural environment by quantifying six behavioural traits up to four times ('trials') in three different contexts, by presenting them with a conspecific intruder, a predator or nothing inside a tube. We found only moderate within-context repeatability (intraclass correlation coefficients) of the focal individual's behaviour, except for attacking either the conspecific or the predator inside the tube. The focal individual's attack rate of the tube was also positively affected by its group size. Averaging traits per context removed the between-trial variation, and consequently the across-context repeatability was very high for all six traits, except for territory maintenance. Trait values depended significantly on the context, except for territory defence. Consequently, individuals could be classified into different behavioural types based on their reaction towards the tube, but surprisingly, and opposite to laboratory studies in this species, ranging propensity and territory maintenance were not included in this behavioural syndrome. We suggest that more studies are needed to compare standardized focal personality tests (e.g. exploration propensity) with actual behaviour observed in nature (e.g. ranging and dispersal). (C) 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

P>1. Static animal colour patches may function among competitors to minimize conflict escalation over resources, by serving as a signal of resource holding potential or aggressiveness. Empirical evidence for the use of colour patches in conflict resolution is largely restricted to pigment-based colours (melanins and carotenoids) and rarely defines the context in which the signals are used. 2. Here we test whether structural-based ultraviolet (UV) crown colouration functions in conflict resolution among dyads of first-year male blue tits Cyanistes caeruleus in captivity, in a context that is known to favour aggressive individuals. 3. We found that on first encounter in a pairwise context, experimentally UV-reduced males were significantly more likely to lose to control-treated opponents than expected by chance. However, this disparity was less pronounced when conflicts were settled with physical fighting or when the opponent was considerably smaller in size. 4. When the same dyads were tested again several weeks later, but with the UV treatment reversed among opponents, none of the effects remained significant, but instead the winner was most likely to be the individual that won at their first encounter. 5. Our results suggest that structural-based UV colouration can affect the outcome of an interaction, but that size differences and the outcome of initial interactions between opponents can override the influence of this signal in conflict resolution. Whether there is a functional basis to maintain a link between aggressiveness and colouration may thus be highly dependent on the general context under which individuals compete in the wild.

P>1. Static animal colour patches may function among competitors to minimize conflict escalation over resources, by serving as a signal of resource holding potential or aggressiveness. Empirical evidence for the use of colour patches in conflict resolution is largely restricted to pigment-based colours (melanins and carotenoids) and rarely defines the context in which the signals are used.2. Here we test whether structural-based ultraviolet (UV) crown colouration functions in conflict resolution among dyads of first-year male blue tits Cyanistes caeruleus in captivity, in a context that is known to favour aggressive individuals.3. We found that on first encounter in a pairwise context, experimentally UV-reduced males were significantly more likely to lose to control-treated opponents than expected by chance. However, this disparity was less pronounced when conflicts were settled with physical fighting or when the opponent was considerably smaller in size.4. When the same dyads were tested again several weeks later, but with the UV treatment reversed among opponents, none of the effects remained significant, but instead the winner was most likely to be the individual that won at their first encounter.5. Our results suggest that structural-based UV colouration can affect the outcome of an interaction, but that size differences and the outcome of initial interactions between opponents can override the influence of this signal in conflict resolution. Whether there is a functional basis to maintain a link between aggressiveness and colouration may thus be highly dependent on the general context under which individuals compete in the wild.

Winner and loser effects, in which the outcome of an aggressive encounter influences the tendency to escalate future conflicts, have been documented in many taxa, but we have limited understanding of why they have evolved. One possibility is that individuals use previous victories and defeats to assess their fighting ability relative to others. We explored this idea by modelling a population of strong and weak individuals that do not know their own strength, but keep track of how many fights they have won. Under these conditions, adaptive behaviour generates clear winner and loser effects: individuals who win fights should escalate subsequent conflicts, whereas those who lose should retreat from aggressive opponents. But these effects depend strongly on age and experience. Young, naive individuals should show highly aggressive behaviour and pronounced loser effects. For these inexperienced individuals, fighting is especially profitable because it yields valuable information about their strength. Aggression should then decline as an individual ages and gains experience, with those who lose fights becoming more submissive. Older individuals, who have a better idea of their own strength, should be more strongly influenced by victories than losses. In conclusion, we predict that both aggressiveness and the relative magnitude of winner and loser effects should change with age, owing to changes in how individuals perceive their own strength.

The present studies investigated why video racing games increase players’ risk-taking inclinations. Four studies reveal that playing video racing games increases risk taking in a subsequent simulated road traffic situation, as well as risk-promoting cognitions and emotions, blood pressure, sensation seeking, and attitudes toward reckless driving. Study 1 ruled out the role of experimental demand in creating such effects. Studies 2 and 3 showed that the effect of playing video racing games on risk taking was partially mediated by changes in self-perceptions as a reckless driver. These effects were evident only when the individual played racing games that reward traffic violations rather than racing games that do not reward traffic violations (Study 3) and when the individual was an active player of such games rather than a passive observer (Study 4). In sum, the results underline the potential negative impact of racing games on traffic safety.

Relations among externalizing behavior, therapeutic context (community care vs. residential care), and social problem-solving by children with mild intellectual disabilities or borderline intelligence were examined. Participants were 186 children (12 to 14 years of age) who responded to a video-based social problem-solving task. Of these, 130 received residential care and the majority suffered from severe externalizing behavior problems. The results indicated that externalizing behavior was related to encoding, generation of aggressive responses, and negative evaluation of assertive responses. Therapeutic context was related to encoding, positive evaluation of assertive responses, and negative evaluation of aggressive responses. Results indicate a discrepancy between appropriate problem-solving skills and behavior in daily life. Implications for interventions are discussed.

Susan Hurley has argued against a well known argument for freedom of speech, the argument from autonomy, on the basis of two hypotheses about violence in the media and aggressive behaviour. The first hypothesis says that exposure to media violence causes aggressive behaviour; the second, that humans have an innate tendency to copy behaviour in ways that bypass conscious deliberation. I argue, first, that Hurley is not successful in setting aside the argument from autonomy. Second, I show that the empirical data are irrelevant to statutory regulation of media violence. They do not yield a sufficiently strong correlation between exposure to media violence and non-autonomously copied criminal violence, and they do not yield a way ex ante to individuate the viewers who will be affected by media violence.

This article describes preschool social understanding and difficult behaviors (hot temper, disobedience, bossiness and bullying) as predictors of oppositional defiant disorder (ODD) and aggressive conduct disorder (ACD) in a Dutch population sample of (pre)adolescents (N = 1943), measured at age 10-12 and at age 13-15. ODD and ACD were assessed by the Child Behavior Checklist and the Youth Self-Report, preschool behavior was evaluated by the parental questionnaire [Symbol: see text]How was your child as a preschooler? (age 4-5)'. Adjusted for each other, all difficult preschool behaviors except bullying were associated with adolescent ODD, while only bullying significantly predicted adolescent ACD. Furthermore, the results suggest a qualitative difference between ODD and ACD in terms of the social component of the disorders: poor preschool social understanding was associated with the development of ACD but not of ODD; and poor social understanding interacted with difficult preschool behaviors to predict later ACD but not ODD. The associations did not differ between boys and girls, and were roughly similar for preadolescent (age 10-12) and early adolescent (age 13-15) outcomes. The finding that poor social understanding was implicated in the development of ACD but not in the development of ODD may help to demarcate the individuality of each disorder and offer leads for (differential) treatment strategies.

Rats are highly social animals and social play during adolescence has an important role for social development, hence post-weaning social isolation is widely used to study the adverse effects of juvenile social deprivation and to induce behavioral phenotypes relevant to neuropsychiatric disorders, like schizophrenia. Communication is an important component of the rat's social behavior repertoire, with ultrasonic vocalizations (USV) serving as situation-dependent affective signals. High-frequency 50-kHz USV occur in appetitive situations and induce approach behavior, supporting the notion that they serve as social contact calls; however, post-weaning isolation effects on the behavioral changes displayed by the receiver in response to USV have yet to be studied. We therefore investigated the impact of post-weaning isolation on socio-affective information processing as assessed by means of our established 50-kHz USV radial maze playback paradigm. We showed that post-weaning social isolation specifically affected the behavioral response to playback of pro-social 50-kHz but not alarm 22-kHz USV. While group-housed rats showed the expected preference, i.e., approach, toward 50-kHz USV, the response was even stronger in short-term isolated rats (i.e., 1 day), possibly due to a higher level of social motivation. In contrast, no approach was observed in long-term isolated rats (i.e., 4 weeks). Importantly, deficits in approach were reversed by peer-mediated re-socialization and could not be observed after post-adolescent social isolation, indicating a critical period for social development during adolescence. Together, these results highlight the importance of social experience for affiliative behavior, suggesting a critical involvement of play behavior on socio-affective information processing in rats. ispartof: FRONTIERS IN BEHAVIORAL NEUROSCIENCE vol:9 ispartof: location:Switzerland status: published

The goal of this article is to examine whether mouse lines genetically selected for short and long attack latencies are good animal models for antisocial behavior in humans. To this end, we compared male Short and Long Attack Latency mice (SAL and LAL, respectively) with the extremes of the Dunedin Multidisciplinary Health and Development Study (men who persistently displayed antisocial behavior [Persisters] and men who never manifested antisocial behavior [Abstainers]). Groups were compared on the basis of five distinct domains: aggression/violence, reproduction, cognition, behavioral disorders, and endophenotypes. Our observations point to considerable parallels between, on one side, SAL and Persisters, and, on the other side, between LAL and Abstainers (but to a lesser extent). We believe that SAL and LAL are good mouse models to study the development of antisocial behavior and will yield valuable and testable hypotheses with regard to the neurobiological and genetical architecture of antisocial behavior.

Although relations between 2D:4D and dominance rank in both baboons and rhesus macaques have been observed, evidence in humans is mixed. Whereas behavioral patterns in humans have been discovered that are consistent with these animal findings, the evidence for a relation between dominance and 2D:4D is weak or inconsistent. The present study provides experimental evidence that male 2D:4D is related to dominance after (fictitious) male-male interaction when the other man has a dominant, but not a submissive or neutral face. This finding provides evidence that the relationship between 2D:4D and dominance emerges in particular, predictable situations and that merely dominant facial characteristics of another person are enough to activate supposed relationships between 2D:4D and dominance. ispartof: PLOS ONE vol:10 issue:11 ispartof: location:United States status: published

Background Corticotrophin-releasing hormone receptor-1 gene (CRHR1) variants have been implicated in mental health. However, little is known of the effects of CRHR1 on long-term mental health and behavior in presence of environmental stressors. We assess the effects of CRHR1 variant (rs17689918)-by-environment interactions on emotionality and behavioral traits, including anxiety, depression, aggression and antisocial behaviors. We also determine effects of rs17689918-by-environment-by-sex interactions on the above-mentioned outcomes. Methods Genotypic assessments were carried out in 564 children (mean age 10 years, 52.5% females) from the ongoing longitudinal Estonian Children Personality Behaviour and Health Study (ECPBHS). Information on stressful life events and family relationships were available at baseline and information on behavioral and mental health outcomes (self- and parent-reports) were available at follow-up ages of 18 and 25 years. ANOVAs were used to determine associations of two-way CRHR1-by-environment and three-way CRHR1-by-sex-by-environment interactions on behavioral and mental health outcomes. Results Two-way CRHR1 interaction effects showed associations between low familial warmth and hostility in individuals with the GG genotype. Associations of low familial warmth with aggression, of higher number of stressful life events with aggression, and of stressful live events with anxious-depressive symptoms were noted in male A-allele carriers and female GG homozygotes. Conclusion CRHR1-by-familial environment interactions influence both outwardly-directed aggression as well as mood and anxiety disorder symptoms in a sex-specific manner. The type of environmental stressor can also influence effects of CRHR1 on behavioral and mental health outcomes.

Background Borderline personality disorder (BPD) is characterised by difficulties with impulse control and affective dysregulation. It is unclear whether BPD contributes to the perpetration of violence or whether this is explained by comorbidity. We explored independent associations between categorical and dimensional representations of BPD and violence in the general population, and differential associations from individual BPD criteria. Methods We used a representative combined sample of 14,753 men and women from two British national surveys of adults (≥16 years). BPD was assessed using the Structured Clinical Interview II- Questionnaire. We measured self-reported violent behaviour in the past 5 years, including severity, victims and locations of incidents. Associations for binary, dimensional and trait-level exposures were performed using weighted logistic regression, adjusted for demography and comorbid psychopathology. Results Categorical diagnosis of BPD was associated only with intimate partner violence (IPV). Associations with serious violence leading to injuries and repetitive violence were better explained by comorbid substance misuse, anxiety and antisocial personality disorder (ASPD). However, anger and impulsivity BPD items were independently associated with most violent outcomes including severity, repetition and injury; suicidal behaviours and affective instability were not associated with violence. Both trait-level and severity-dimensional analyses showed that BPD symptoms might impact males and females differently in terms of violence. Conclusions For individuals diagnosed BPD, violence is better explained by comorbidity. However, BPD individual traits show different pathways to violence at the population level. Gender differences in BPD traits and their severity indicate distinct, underlying mechanisms towards violence. BPD and traits should be evaluated in perpetrators of IPV.

Background: Patient violence against nurses in their work environments is a widespread global concern, particularly in the field of mental health care. A high prevalence of violent events impacts the well-being of nurses and may also impair overall ward climate. However, it has been proposed that nurses' use limited techniques to prevent patient violence, and, therefore, more comprehensive methods for dealing with patient violence are needed. There is still restricted understanding of the ward climate during the occurrence of a violent event as well as how these incidents could be more effectively prevented. This study aimed to explore nurses' experiences of violent events in psychiatric wards, give insight into ward climates and examine suggestions for violence prevention. Methods: This study employed a descriptive, exploratory design including focus groups (n = 5) and open-ended questions. The participants were registered and enrolled nurses (n = 22) working on three closed psychiatric inpatient wards in one Finnish hospital district. Focus groups were tape-recorded, transcribed and analyzed with inductive content analysis. Results: Nurses' experiences of violent events included a variety of warning signs and high-risk situations which helped them to predict forthcoming violence. Patient-instigated violent events were described as complicated situations involving both nurses and patients. When the wards were overloaded with work or emotions, or if nurses had become cynical from dealing with such events, well-being of nurses was impaired and nursing care was complicated. Suggestions for violence prevention were identified, and included, for example, more skilled interaction between nurses and patients and an increase in contact between nurses and patients on the ward. Conclusions: This study revealed the complexity of violent events on psychiatric wards as well as the implications of these events on clinical practice development and training, administration and policy. A routine process is needed through which nurses' experiences and ideas concerning prevention of violent events are acknowledged.