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The video deficit is a well-documented effect whereby children learn less well about information delivered via a screen than the same information delivered in person. Research suggests that increasing social contingency may ameliorate this ‘video deficit’ (Nielsen et al., 2008). The current study instantiated social contingency to screen-based information by embodying the screen within a socially interactive robot. We failed to document any difference between 22- to 26-month-old children’s (N = 80) imitation of screen-based information embedded in a social robot and in person humans. Further, we were unable to replicate the video deficit with children imitating at similar levels regardless of the presentation medium. This failure to replicate supports the findings of a recent meta-analysis of video deficit research whereby there appears to be a steady decrease over time in the magnitude of the video deficit effect. We postulate that the video deficit may soon be a historical artifact as children begin perceiving technology as relevant and meaningful in everyday life more and more. This research finds that observational-based learning material can be successfully delivered in person, via a screen, or via a screen embedded in a social robot.

We examined Turkish participants’ mindreading accuracy toward ingroup versus outgroup targets. Three hundred and fifty-four Turkish participants were randomly assigned to one of three target groups: Turkish, Syrian, or Norwegian. The mindreading accuracy for these targets was measured along with the perceived cultural similarity of the target to the ingroup, as well as prejudice and threat perception. Participants evidenced higher mindreading accuracy toward Turkish targets compared with Syrian and Norwegian targets. Mindreading accuracy for the Syrian and Norwegian targets did not differ, but lower perceived similarity to the Turkish ingroup significantly predicted lower mentalizing for Syrian and Norwegians. In the Syrian target group, lower perceived similarity interacted with lower education and higher prejudice, resulting in a further reduction in mindreading. For Norwegian targets, lower similarity impaired mindreading through an interaction with higher threat perception. Results indicate that even when mentalizing capacity is mature, intergroup factors are linked with the deployment of mindreading.

Objective\ud To evaluate changes in electronic screen-based media use in 3- to 7-year-old children across 6 countries as a result of the coronavirus disease 2019 (COVID-19) pandemic.\ud \ud Study design\ud Between April and July 2020, parents of 2516 children completed online survey measures reporting current (“now”) and retrospective (“before the pandemic”) screen-based media use for the purposes of entertainment, educational app use, and socializing with family and friends. Parents also reported family socioeconomic characteristics and impacts of the pandemic to their physical wellbeing (eg, whether a family member or friend had been diagnosed with COVID-19) and social disruption (eg, whether family experienced a loss of income or employment due to the pandemic).\ud \ud Results\ud On average, children engaged with screens more than 50 minutes more during the pandemic than before. This was largely driven by increases in screen use for entertainment purposes (nearly 40 minutes) and for use of educational apps (over 20 minutes). There was no overall change in screen use for socializing with family and friends. Children from lower socioeconomic status households increased screen use both for entertainment and educational app use more so than did children from higher socioeconomic status households.\ud \ud Conclusions\ud The global pandemic caused by COVID-19 has increased overall electronic screen-based media use. As lives become increasingly digital by necessity, further research is needed to better understand positive and negative consequences of electronic screen-based media use.

Neonatal imitation is a cornerstone in many theoretical accounts of human development and social behavior, yet its existence has been debated for the past 40 years. To examine possible explanations for the inconsistent findings in this body of research, we conducted a multilevel meta-analysis synthesizing 336 effect sizes from 33 independent samples of human newborns, reported in 26 articles. The meta-analysis found significant evidence for neonatal imitation ( d = 0.68, 95% CI = [0.39, 0.96], p < .001) but substantial heterogeneity between study estimates. This heterogeneity was not explained by any of 13 methodological moderators identified by previous reviews, but it was associated with researcher affiliation, test of moderators ( QM) (15) = 57.09, p < .001. There are at least two possible explanations for these results: (a) Neonatal imitation exists and its detection varies as a function of uncaptured methodological factors common to a limited set of studies, and (2) neonatal imitation does not exist and the overall positive result is an artifact of high researcher degrees of freedom.

This study explored theory of mind (ToM) development in school-aged deaf children. To address new questions, we gave a standard, well-controlled false-belief test to a large (n = 200) sample of severely-to-profoundly deaf children aged 8–15 years in a non-Western culture (Thailand). There were 190 deaf children of hearing parents and 10 deaf native signers with signing deaf parents, consistent with overall population ratios. Comparing our Thai sample’s ToM performance on standard tests of false-belief understanding with that reported in past studies, our results showed a 67% ToM success rate for Thai severely-to-profoundly deaf children of hearing parents similar to collective findings from past research on smaller samples in Australia, Estonia, France, Great Britain, Sweden, and the United States. Our Thai deaf native signers likewise performed equivalently to native signers of similar age studied in past research in Australia and the United States. Collectively, the detailed findings of our study suggest promising new directions for future studies to pursue in order to build upon this novel and theoretically provocative evidence about how ToM development and ToM delay unfold for school-aged deaf children growing up in varied cultures, school settings, and family circumstances.

We investigated whether embodied ownership is evident in early childhood. To do so, we gifted a drinking bottle to children (aged 24–48 months) to use for 2 weeks. They returned to perform reach–grasp–lift–replace actions with their own or the experimenter’s bottle while we recorded their movements using motion capture. There were differences in motor interactions with self- vs experimenter-owned bottles, such that children positioned self-owned bottles significantly closer to themselves compared with the experimenter’s bottle. Age did not modulate the positioning of the self-owned bottle relative to the experimenter-owned bottle. In contrast, the pattern was not evident in children who selected one of the two bottles to keep only after the task was completed, and thus did not ‘own’ it during the task (Experiment 2). These results extend similar findings in adults, confirming the importance of ownership in determining self–other differences and provide novel evidence that object ownership influences sensorimotor processes from as early as 2 years of age.

The current sentence is in the discussion (sub-section The role of pre-conception maternal depression) and reads: "Pre-conception treatment of mental health issues is also associated with substantial savings in health care costs (Chojenta et al., 2018)."

The Observation of Human-Animal Interaction for Research (OHAIRE) is a coding tool developed to capture the behavior of children when interacting with social partners and animals in naturalistic settings. The OHAIRE behavioral categories of focus are emotional displays, social communication behaviors toward adults and peers, behaviors directed toward animals or experimental control objects, and interfering behaviors. To date, the OHAIRE has been used by 14 coders to code 2,732 min of video across four studies with a total of 201 participants ages 5 to 18 years (M = 10.1, SD = 2.5). Studies involved animal-assisted intervention with three species (i.e., dogs, horses, and guinea pigs) and three populations (i.e., autism spectrum disorder, attention-deficit hyperactivity disorder, and typically developing children) in a school, a therapeutic horseback riding program, a group therapy program, and the hospital setting. We explored the psychometric properties of the OHAIRE through analyses of its inter-rater reliability, intra-rater reliability, convergent and divergent validity, and internal structure, using data from these four human-animal interaction studies. The average inter-rater reliability was excellent (kappa = 0.81), with good reliability in most of the behavioral categories coded. Intra-rater reliability was consistently excellent (0.87 ≤ kappa ≤0.96). Internal structure analyses with Cronbach's alpha supported the exploratory use of subscales to measure social communication behaviors toward peers (α = 0.638) and adults (α = 0.605), and interactions experimental control objects (α = 0.589), and the use of a subscale to measure interactions with animals (α = 0.773). Correlation analyses with multiple questionnaires showed a convergence between positive emotional display and social behaviors as assessed by the OHAIRE and social skills as assessed by the Social Skills Rating System (SSRS) and the Social Communication Questionnaires (SCQ). Little concordance was found between the OHAIRE and the Social Responsiveness Scale (SRS) or the Aberrant Behavior Checklist-Community (ABC). The OHAIRE shows promise for wider use in the field of Human-Animal Interaction, with a need for generalization across more settings and ages.

Human children copy others' actions with high fidelity, supporting early cultural learning and assisting in the development and maintenance of behavioral traditions [1]. Imitation has long been assumed to occur from birth [2-4], with influential theories (e.g., [5-7]) placing an innate imitation module at the foundation of social cognition (potentially underpinned by a mirror neuron system [8, 9]). Yet, the very phenomenon of neonatal imitation has remained controversial. Empirical support is mixed and interpretations are varied [10-16], potentially because previous investigations have relied heavily on cross-sectional designs with relatively small samples and with limited controls [17, 18]. Here, we report surprising results from the most comprehensive longitudinal study of neonatal imitation to date. We presented infants (n = 106) with nine social and two non-social models and scored their responses at 1, 3, 6, and 9 weeks of age. Longitudinal analyses indicated that the infants did not imitate any of the models, as they were just as likely to produce the gestures in response to control models as they were to matching models. Previous positive findings were replicated in limited cross-sections of the data, but the overall analyses confirmed these findings to be mere artifacts of restricted comparison conditions. Our results undermine the idea of an innate imitation module and suggest that earlier studies reporting neonatal imitation were methodologically limited.

In the last century, decreases in infant and child mortality, urbanization and increases in healthcare efficacy have reduced children's personal exposure to death and dying. So how do children acquire accurate conceptions of death in this context? In this paper, we discuss three sources of children's learning about death and dying, namely, direct experience of death, parental communication about death and portrayals of death in the media and the arts. We conclude with recommendations about how best to teach modern children about this aspect of life. This article is part of the theme issue ‘Evolutionary thanatology: impacts of the dead on the living in humans and other animals’.

Children with autism spectrum disorder (ASD) experience high rates of social stress and anxious arousal. Preliminary evidence suggests that companion animals can act as buffers against the adverse effects of social stress in adults. We measured continuous physiological arousal in children with ASD and typically developing (TD) children in a social context during four conditions: (a) a baseline of reading silently, (b) a scripted classroom activity involving reading aloud, (c) free play with peers and toys, and (d) free play with peers and animals (guinea pigs). Our results confirmed heightened arousal among children with ASD compared to TD children in all conditions, except when the animals were present. Children with ASD showed a 43% decrease in skin conductance responses during free play with peers in the presence of animals, compared to toys. Thus, animals may act as social buffers for children with ASD, conferring unique anxiolytic effects.

Fink, Begeer, Peterson, Slaughter, and de Rosnay (2014) conducted a prospective longitudinal study showing that theory-of-mind (ToM) development at school entry (mean age 5.61 years) significantly predicted friendlessness both concurrently and 2 years later. Friendlessness (defined as lacking any friendship that is mutually reciprocated) is conceptually and empirically distinct from group popularity and independently predicts adverse mental health outcomes throughout life. Here, we respond to the thoughtful commentaries by Wellman (Brit. J. Dev. Psychol, 2015; 33, 24-26), Mizokawa and Koyasu (Brit. J. Dev. Psychol, 2015; 33, 21-23), and Lerner and Lillard (Brit. J. Dev. Psychol, 2015; 33, 18-20) with a focus on three key issues, namely (a) the definition and measurement of friendship, (b) the measurement of advanced ToM development beyond the preschool years, and (c) the exciting future potential for ToM-based training and intervention studies to combat chronic friendlessness.

Una pregunta que aún se mantiene sin responder dentro de la literatura de Teoría de la Mente es si experimentamos limitaciones para entender y atribuir estados mentales a personas que pertenezcan a culturas diferentes a la nuestra. Para responder este interrogante, un estudio reciente de nuestro laboratorio proporcionó evidencia sobre cómo la pertenencia a una misma cultura o a culturas diferentes influye sobre el grado de precisión y el tiempo de generación de explicaciones mentalistas que damos a la conducta de los demás. Los resultados sugieren que somos más lentos y menos precisos al interpretar en términos mentalistas el comportamiento de personas pertenecientes a grupos culturales diferentes al nuestro.

There is now considerable evidence that neurotypical individuals track the internal cognitions of others, even in the absence of instructions to do so. This finding has prompted the suggestion that humans possess an implicit mental state tracking system (implicit Theory of Mind, ToM) that exists alongside a system that allows the deliberate and explicit analysis of the mental states of others (explicit ToM). Here we evaluate the evidence for this hypothesis and assess the extent to which implicit and explicit ToM operations are distinct. We review evidence showing that adults can indeed engage in ToM processing even without being conscious of doing so. However, at the same time, there is evidence that explicit and implicit ToM operations share some functional features, including drawing on executive resources. Based on the available evidence, we propose that implicit and explicit ToM operations overlap and should only be considered partially distinct.

The objective of this study was to implement and evaluate a classroom-based Animal-Assisted Activities (AAA) program on social functioning in children with autism spectrum disorder (ASD).This was a multisite, control-to-intervention design study.The study was conducted in 41 classrooms in 15 schools in Brisbane, Australia.Sixty-four (64) 5- to 12-year-old children diagnosed with ASD comprised the study group.The AAA program consisted of 8 weeks of animal exposure in the school classroom in addition to 16 20-minute animal-interaction sessions.Teacher- and parent-reported child behavior and social functioning were assessed through standardized instruments at three time points: upon study entry (Time 1), after an 8-week waiting period during the week prior to the AAA program (Time 2), and during the week following the 8-week AAA program (Time 3).Significant improvements were identified in social functioning, including increases in social approach behaviors and social skills, and decreases in social withdrawal behaviors, from before to after the AAA program, but not during the waitlist period. Over half of parents also reported that participants demonstrated an increased interest in attending school during the program.Results demonstrate the feasibility and potential efficacy of a new classroom-based Animal-Assisted Activities model, which may provide a relatively simple and cost-effective means of helping educators and families to improve the social functioning of children with ASD.

Children aged 3–12 years (n = 184) with typical development, deafness, autism, or Asperger syndrome took a series of theory-of-mind (ToM) tasks to confirm and extend previous developmental scaling evidence. A new sarcasm task, in the format of H. M. Wellman and D. Liu’s (2004) 5-step ToM Scale, added a statistically reliable 6th step to the scale for all diagnostic groups. A key previous finding, divergence in task sequencing for children with autism, was confirmed. Comparisons among diagnostic groups, controlling age, and language ability, showed that typical developers mastered the 6 ToM steps ahead of each of the 3 disabled groups, with implications for ToM theories. The final (sarcasm) task challenged even nondisabled 9-year-olds, demonstrating the new scale’s sensitivity to post-preschool ToM growth.

In 2 studies mothers read wordless storybooks to their preschool-aged children; narratives were analyzed for mental state language. Children's theory-of-mind understanding (ToM) was concurrently assessed. In Study 1, children's (N=30; M age 3 years 9 months) ToM task performance was significantly correlated with mothers' explanatory, causal, and contrastive talk about cognition, but not with mothers' simple mentions of cognition. In Study 2, the same pattern was found in an older sample of typically developing children (N=24; M age 4 years 7 months), whereas for children on the autism spectrum (N=24; M age 6 years 7.5 months), ToM task performance was uniquely correlated with mothers' explanatory, causal, and contrastive talk about emotions.

Three studies (N=144) investigated how toddlers aged 18 and 24 months pass the surprise-mark test of self-recognition. In Study 1, toddlers were surreptitiously marked in successive conditions on their legs and faces with stickers visible only in a mirror. Rates of sticker touching did not differ significantly between conditions. In Study 2, toddlers failed to touch a sticker on their legs that had been disguised before being marked. In Study 3, having been given 30-s exposure to their disguised legs before testing, toddlers touched the stickers on their legs and faces at equivalent levels. These results suggest that toddlers pass the mark test based on expectations about what they look like, expectations that are not restricted to the face.

Human faces and bodies are both complex and interesting perceptual objects, and both convey important social information. Given these similarities between faces and bodies, we can ask how similar are the visual processing mechanisms used to recognize them. It has long been argued that faces are subject to dedicated and unique perceptual processes, but until recently, relatively little research has focused on how we perceive the human body. Some recent paradigms indicate that faces and bodies are processed differently; others show similarities in face and body perception. These similarities and differences depend on the type of perceptual task and the level of processing involved. Future research should take these issues into account.

Research with adults has shown a preference for average-weight female figures with waist-to-hip ratios (WHR) of 0.7, and average weight male figures with waist-to-hip ratios of 0.9. This study investigated the development of preferences for WHR sizes as well as preferences for specific body weights. Five-hundred eleven children ranging in age from 6 to 17 were presented with drawings of 12 male and 12 female silhouettes varying in weight and WHR and asked to select one they thought looked the nicest or most attractive. The youngest children showed preferences for the underweight figures, changing to consistent preferences for the average weight figures in the teenage years. The developmental curves for waist-to-hip ratio preferences were linear, changing gradually over time to become more adult-like. Potential developmental models for the development of preferences for specific body shapes are considered in relation to these data.

Eye-movement patterns in 'Sally-Anne' tasks reflect humans' ability to implicitly process the mental states of others, particularly false-beliefs - a key theory of mind (ToM) operation. It has recently been proposed that an efficient ToM system, which operates in the absence of awareness (implicit ToM, iToM), subserves the analysis of belief-like states. This contrasts to consciously available belief processing, performed by the explicit ToM system (eToM). The frontal, temporal and parietal cortices are engaged when humans explicitly 'mentalize' about others' beliefs. However, the neural underpinnings of implicit false-belief processing and the extent to which they draw on networks involved in explicit general-belief processing are unknown. Here, participants watched 'Sally-Anne' movies while fMRI and eye-tracking measures were acquired simultaneously. Participants displayed eye-movements consistent with implicit false-belief processing. After independently localizing the brain areas involved in explicit general-belief processing, only the left anterior superior temporal sulcus and precuneus revealed greater blood-oxygen-level-dependent activity for false- relative to true-belief trials in our iToM paradigm. No such difference was found for the right temporal-parietal junction despite significant activity in this area. These findings fractionate brain regions that are associated with explicit general ToM reasoning and false-belief processing in the absence of awareness.

Background Previous research has demonstrated the capacity of animal presence to stimulate social interaction among humans. The purpose of this study was to examine the interactions of children with autism spectrum disorder (ASD) with an adult and their typically-developing peers in the presence of animals (two guinea pigs) compared to toys. Methods Ninety-nine children from 15 classrooms in 4 schools met the inclusion criteria and participated in groups of three (1 child with ASD and 2 typically-developing peers). Each group was video-recorded during three 10-minute, free-play sessions with toys and three 10-minute, free-play sessions with two guinea pigs. Two blinded observers coded the behavior of children with ASD and their peers. To account for the nested study design, data were analyzed using hierarchical generalized linear modeling. Results Participants with ASD demonstrated more social approach behaviors (including talking, looking at faces, and making tactile contact) and received more social approaches from their peers in the presence of animals compared to toys. They also displayed more prosocial behaviors and positive affect (i.e., smiling and laughing) as well as less self-focused behaviors and negative affect (i.e., frowning, crying, and whining) in the presence of animals compared to toys. Conclusions These results suggest that the presence of an animal can significantly increase positive social behaviors among children with ASD.

This study investigated the effects of a classroom-based animal-assisted activities (AAA) program with guinea pigs on the social functioning of primary school children. We hypothesized that participants in the experimental condition (n = 64), compared with a waitlist control group (n = 64), would demonstrate improvements in social functioning following the program. Parents and teachers used the Social Skills Rating System (SSRS) to evaluate the social skills and problem behaviors of 128 participating children (age range = 4.8 to 12.7 years) before and after an 8-week period. Teachers also rated academic competence at both time points. Children who participated in the AAA program demonstrated significantly greater improvements in social functioning than their control group peers, as defined by greater increases in social skills (teacher SSRS) and decreases in problem behaviors (parent and teacher SSRS). There were no significant differences between the groups in academic competence. AAA participants demonstrated significant increases in social skills and decreases in problem behaviors from pre- to post-program on the teacher version of the SSRS. Control group participants did not show significant changes on these measures. These findings suggest that an AAA program with guinea pigs may be a feasible addition to the primary school classroom in order to improve social functioning. Further component analysis will be necessary to determine whether the animal is the active ingredient in AAA programs of this nature.

Intuitive theories are defined as coherently interrelated systems of concepts that generate explanations and predictions in a particular domain of experience. 2 studies tested whether the child's theory of mind can be characterized as an intuitive theory. In Study 1, 3-year-old children who did not pass a false belief pretest were trained in 2 groups: (1) on the concept of belief, or (2) on the related concepts of desire and perception. Training took place over 2 weeks, with children given mental state tasks and receiving feedback according to their performance. Both training groups showed improved false belief performance on the posttest, compared to a control group trained on number conservation. This result is interpreted as demonstrating coherence in the child's theory of mind. In Study 2, these findings were repeated and expanded: training on belief as well as training on desire and perception resulted in improved performance on a variety of standard theory of mind posttests. Results are discussed with respect to competing theories of children's intuitive psychological knowledge.

Adult humans demonstrate differential processing of stimuli that were recurrent threats to safety and survival throughout evolutionary history. Recent studies suggest that differential processing of evolutionarily ancient threats occurs in human infants, leading to the proposal of an inborn mechanism for rapid identification of, and response to, evolutionary fear-relevant stimuli. The current study provides novel data in support of this proposal, showing for the first time that human infants differentially process evolutionary threats presented in the auditory modality. Sixty-one 9-month-olds listened to evolutionary fear-relevant, modern fear-relevant, and pleasant sounds, while their heart rate, startle, and visual orienting behaviours were measured. Infants demonstrated significantly enhanced heart rate deceleration, larger eye-blinks, and more visual orienting when listening to evolutionary fear-relevant sounds compared to sounds from the other two categories. These results support the proposal that human infants possess evolved mechanisms for the differential processing of a range of ancient environmental threats.

We used a preferential looking paradigm to evaluate infants' preferences for correct versus incorrect counting. Infants viewed a video depicting six fish. In the correct counting sequence, a hand pointed to each fish in turn, accompanied by verbal counting up to six. In the incorrect counting sequence, the hand moved between two of the six fish while there was still verbal counting to six, thereby violating the one-to-one correspondence principle of correct counting. Experiment 1 showed that Australian 18 month olds, but not 15 month olds, significantly preferred to watch the correct counting sequence. In experiment 2, Australian infants' preference for correct counting disappeared when the count words were replaced by beeps or by Japanese count words. In experiment 3, Japanese 18 month olds significantly preferred the correct counting video only when counting was in Japanese. These results show that infants start to acquire the abstract principles governing correct counting prior to producing any counting behaviour.

3-year-old children have difficulty reporting their past false beliefs. We investigated their ability to remember and report other types of past mental state, in particular, pretenses, images, perceptions, desires, and intentions. In a series of tasks, children were placed in one mental state, that state was changed, and they were asked to report the initial state. 4-year-olds were generally able to report all their past mental states, including beliefs. 3-year-olds were able to report past pretenses, images, and perceptions extremely well. They had great difficulty reporting past beliefs. Reporting past desires and intentions was more difficult than reporting pretenses, images, and perceptions, but slightly less difficult than reporting beliefs. The evidence suggests that 3-year-olds have difficulty understanding the nature of representation.

As a knowable object, the human body is highly complex. Evidence from several converging lines of research, including psychological studies, neuroimaging and clinical neuropsychology, indicates that human body knowledge is widely distributed in the adult brain, and is instantiated in at least three partially independent levels of representation. Sensorimotor body knowledge is responsible for on-line control and movement of one's own body and may also contribute to the perception of others' moving bodies; visuo-spatial body knowledge specifies detailed structural descriptions of the spatial attributes of the human body; and lexical-semantic body knowledge contains language-based knowledge about the human body. In the first chapter of this Monograph, we outline the evidence for these three hypothesized levels of human body knowledge, then review relevant literature on infants' and young children's human body knowledge in terms of the three-level framework. In Chapters II and III, we report two complimentary series of studies that specifically investigate the emergence of visuo-spatial body knowledge in infancy. Our technique is to compare infants'responses to typical and scrambled human bodies, in order to evaluate when and how infants acquire knowledge about the canonical spatial layout of the human body. Data from a series of visual habituation studies indicate that infants first discriminate scrambled from typical human body picture sat 15 to 18 months of age. Data from object examination studies similarly indicate that infants are sensitive to violations of three-dimensional human body stimuli starting at 15-18 months of age. The overall pattern of data supports several conclusions about the early development of human body knowledge: (a) detailed visuo-spatial knowledge about the human body is first evident in the second year of life, (b) visuo-spatial knowledge of human faces and human bodies are at least partially independent in infancy and (c) infants' initial visuo-spatial human body representations appear to be highly schematic, becoming more detailed and specific with development. In the final chapter, we explore these conclusions and discuss how levels of body knowledge may interact in early development.

Two studies demonstrate dissociation between children's understanding of pictorial representations (photos and drawings) and mental representations (beliefs). In Study 1, 37 preschoolers were tested on false belief, appearance-reality, false photo, and false drawing tasks. The false picture tasks were significantly easier, and no correlation was found between children's performances on false belief and false picture tasks. In Study 2, 30 children who failed a false belief pretest were randomly assigned to 3 training groups: Belief (trained on false belief tasks), Picture (trained on false picture tasks), or Control (trained on number conservation tasks). Training was conducted in 2 sessions over the course of 2 weeks; tasks were presented and feedback was provided. All children were posttested on theory of mind tasks, false picture tasks, and a number conservation task. The posttest results showed differential patterns of performance, with the Belief group scoring highest on the theory of mind posttests, the Picture group scoring highest on the false picture posttests, and the Control group scoring highest on the number conservation posttest. Results are discussed with respect to competing models of theory of mind development.

As a knowable object, the human body is highly complex. Evidence from several converging lines of research, including psychological studies, neuroimaging and clinical neuropsychology, indicates that human body knowledge is widely distributed in the adult brain, and is instantiated in at least three partially independent levels of representation. Sensorimotor body knowledge is responsible for on-line control and movement of one's own body and may also contribute to the perception of others' moving bodies; visuo-spatial body knowledge specifies detailed structural descriptions of the spatial attributes of the human body; and lexical-semantic body knowledge contains language-based knowledge about the human body. In the first chapter of this Monograph, we outline the evidence for these three hypothesized levels of human body knowledge, then review relevant literature on infants' and young children's human body knowledge in terms of the three-level framework. In Chapters II and III, we report two complimentary series of studies that specifically investigate the emergence of visuo-spatial body knowledge in infancy. Our technique is to compare infants'responses to typical and scrambled human bodies, in order to evaluate when and how infants acquire knowledge about the canonical spatial layout of the human body. Data from a series of visual habituation studies indicate that infants first discriminate scrambled from typical human body picture sat 15 to 18 months of age. Data from object examination studies similarly indicate that infants are sensitive to violations of three-dimensional human body stimuli starting at 15-18 months of age. The overall pattern of data supports several conclusions about the early development of human body knowledge: (a) detailed visuo-spatial knowledge about the human body is first evident in the second year of life, (b) visuo-spatial knowledge of human faces and human bodies are at least partially independent in infancy and (c) infants' initial visuo-spatial human body representations appear to be highly schematic, becoming more detailed and specific with development. In the final chapter, we explore these conclusions and discuss how levels of body knowledge may interact in early development.

In the variety of subjective contours that are structured like Kanizsa's triangle, shapes consist partly of edges of elements that make up the patterns that give rise to the subjective contours and partly of the subjective contours. It was found that familiarity with the shape that fit the subjective-contour-inducing pattern in this fashion increased the likelihood that subjective con­ tours were perceived when the "containing" pattern was shown. Six containing patterns were constructed that did not readily yield subjective contours when the fitting shapes were not familiar. It was found that these containing patterns yielded subjective contours considerably more often when their fitting shapes had been made familiar than when they had not been. This result was obtained even though all subjects were acquainted with subjective contours before the contain­ ing patterns were shown, and even though they were asked whether or not they saw subjective contours when they saw the containing patterns. In a second experiment, subjects had no such set to experience subjective contours. When two of the containing patterns that had been used in the first experiment were shown, no subjective contours were perceived. However, after sub­ jects had been familiarized with a drawing of one of the fitting shapes, they saw that shape in the pattern that contained it and along with it the subjective contours. In recent years, subjective contours, also called illu­ sory contours, have been given much attention, and that is as it should be. Whenever percepts have features that do not have their counterparts in proximal stimulation, they are likely to reveal something about the perceptual processes involved. Subjective contours take many forms. They are discussed in a recent review of the large litera­ ture by Parks (1984). Our investigation deals with the kind of patterns that yield subjective contours most reliably when viewed by naive subjects, that is, by those who have not been specifically aware of subjective contours before. In these patterns, subjective contours are more or less straight connections between aligned edges in cutouts that are readily perceived as cutouts, where the subjective con­ tours are parts of edges of simple shapes, such as the up­ right triangle in Figure 1. The outline of the triangle con­ sists of real contours where it shares the edges of the cutouts in the three black disks. Where the outline of the triangle is not provided by stimulation-that is, in the straight connections between the ends of the real contours-subjective contours are seen. These parts ofthe triangle's outline are the perceived features that have no counterpart in stimulation. The pattern that gives rise to subjective contours-in the case of Figure 1 the three black disks and the interrupted outline of the upside-down triangle-has been called a subjective-contour-inducing array and will be referred to as a containingpattern. The figure that is composed in part of subjective contours, here

During prolonged monocular observation from afar, an upright wire cube (Necker cube) or a drawing of such a cube inverts continuously so that the lower of the two frontal faces appears to be either in front (version A) or in back (version B). Version A is perceived as if it were viewed obliquely from above and version B as if seen from below. In our experiments, timing the durations of the versions showed that version A lasted longer than version B. When a wire cube was shifted upward so that it was actually viewed slightly from below, version B lasted longer than version A. The actual viewing direction was apparently taken into account by the subjects, which was not the case when the cube was replaced by a drawing showing the projection of the cube. In that case, version A always lasted longer, regardless of the actual viewing direction. This finding conforms with picture viewing in general, where a three-dimensional object’s orientation does not change when the observer’s viewing direction changes.