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Background: Driving under the influence of alcohol and other drugs contributes significantly to road traffic crashes worldwide. This study explored trends of alcohol, methylamphetamine (MA), 3,4-methylenedioxy-N-methylamphetamine (MDMA) and Δ9-tetrahydrocannabinol (THC), in road crashes from 2010 to 2019 in Victoria, Australia., Methods: We conducted a cross-sectional analysis using data from the Victorian Institute of Forensic Medicine and Victoria Police, examining proscribed drug detections in road crashes. Time series graphs per substance explored indicative trends and comparisons between road users. Negative binomial regression models, with robust SEs and adjusted for exposure (kilometres travelled, Victorian licence holders), modelled the incidence rate ratio, with a Bonferroni-adjusted α=0.007 for multiple comparisons., Results: There were 19 843 injured drivers and 1596 fatally injured drivers. MA had the highest prevalence (12.3% of fatalities and 9.1% of injured drivers), demonstrating an increase over time. Overall, 16.8% of car drivers and motorcyclists tested positive for one or more drugs, with 14% of crashes involving a blood alcohol concentration (BAC)≥0.05%. MA and THC were the most common drugs in fatalities. Between 2015 and 2019, MA was detected in 27.9% of motorcyclist fatalities, followed by THC (18.3%) and alcohol ≥0.05% (14.2%), with similar but lower frequencies among injured motorcyclists. Alcohol detections (≥0.05% BAC) in fatalities declined, but increased in injured motorcyclists and car drivers until plateauing in 2017. THC detections rose among injured drivers until 2018, detected in 8.1% and 15.2% of injured and fatal drivers, respectively. MDMA-positive driving decreased among injured drivers and remained stable at ~1% of fatalities., Conclusions: Despite enhanced road safety measures in Victoria, drug-driving persists, indicating a need for revised prevention strategies targeting this growing issue., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2025. No commercial re-use. See rights and permissions. Published by BMJ Group.)

Sijilmassi et al. suggest that group myths explaining the shared history of a people succeed and propagate by leveraging cognitive cues from fitness interdependence. We offer an alternative and mutually compatible account rooting the success of group myths in cues from a different cognitive domain: The development of self-concepts.

Novel benzodiazepine (NBz) detections in Victorian coronial cases started early in 2018 and have continued to increase in number and type up to December 2022. The 11 different NBz detections included etizolam (n = 82), flualprazolam (n = 43), clonazolam or 8-aminoclonazolam (n = 30), bromazolam (n = 15), clobromazolam (n = 13), phenazepam (n = 13), flubromazolam (n = 12), flubromazepam (n = 8), desalkylflurazepam (n = 6), diclazepam (n = 2), and estazolam (n = 1). The pattern of detections varied over the 5-year period, with different compounds appearing over different time frames. The most recent NBz to appear were bromazolam, clobromazolam, flubromazepam, and phenazepam, whereas etizolam had been seen regularly in case work since 2018. Of the total 133 deaths, 95 were considered drug-related deaths by forensic pathologists with at least one additional CNS depressant also present capable of contributing to death. All deaths involved other (non-benzodiazepine) CNS active drugs, although many involved multiple NBz, with five or more different benzodiazepines detected in eight cases., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site–for further information please contact journals.permissions@oup.com.)

A multi-analyte liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is described, involving the separation of delta-9-tetrahydrocannabinol (delta-9-THC) and delta-8-THC in addition to other commonly encountered drugs and metabolites. Briefly, sample preparation involved an alkaline liquid-liquid extraction (methyl tert-butyl ether) of blood (100 μl). The solvent layer was transferred, evaporated to dryness, reconstituted, and samples then separated on an Agilent Poroshell 120 EC-C18 100 Å (50 mm × 3.0 mm, 2.7 μm) analytical column using a multi-step gradient elution of 50 mM ammonium formate in water (pH 3.5) and 0.1% formic acid in methanol over 14 min. A SCIEX Triple Quad 6500+ system operating in scheduled multiple reaction monitoring and positive electrospray ionization was used for detection. There were no interferences, and matrix effects were generally acceptable (±20% of neat response). Linearity was achieved within the calibration range, including methylamphetamine (MA) (10-1000 ng/ml), 3,4-methylenedioxy-N-methylamphetamine (MDMA) (10-1,000 ng/ml), cocaine (10-1000 ng/ml), and two THC isomers (1-100 ng/ml). Accuracies of MA, MDMA, cocaine, and two THC isomers were 3.6 to 8.9%, -1.2 to 4%, -5.3 to 5.8%, and -11 to 14%, respectively; while precision estimates of the same were 1.6 to 5.4%, 1.7 to 5.3%, 1.2 to 4.5%, and 2 to 10%, respectively. Autosampler stability and dilution integrity were within acceptable limits, and no carryover was detected at the limit of detection. This validated LC-MS/MS method made the routine identification of both delta-9-THC and delta-8-THC in blood possible., (© 2023 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.)

The 30 commentators are largely sympathetic to the account I develop for the origins of peace in humans, though many suggest that peace has deeper roots and that humans share characteristics of peace with other species. Multiple commentators propose how to extend my framework or focus on the cognitive and psychological prerequisites for peace. In my reply, I discuss these considerations and further my account of why I think peace as defined here was unlikely prior to behavioral modernity which emerged approximately 100,000 years ago. In general, there seems to be a consensus that moving the debate beyond "war versus peace" in human evolution and instead focusing on the conditions that enable war or peace is a fruitful direction for the field to take.

Despite the variability of music across cultures, some types of human songs share acoustic characteristics. For example, dance songs tend to be loud and rhythmic, and lullabies tend to be quiet and melodious. Human perceptual sensitivity to the behavioral contexts of songs, based on these musical features, suggests that basic properties of music are mutually intelligible, independent of linguistic or cultural content. Whether these effects reflect universal interpretations of vocal music, however, is unclear because prior studies focus almost exclusively on English-speaking participants, a group that is not representative of humans. Here, we report shared intuitions concerning the behavioral contexts of unfamiliar songs produced in unfamiliar languages, in participants living in Internet-connected industrialized societies (n = 5,516 native speakers of 28 languages) or smaller-scale societies with limited access to global media (n = 116 native speakers of three non-English languages). Participants listened to songs randomly selected from a representative sample of human vocal music, originally used in four behavioral contexts, and rated the degree to which they believed the song was used for each context. Listeners in both industrialized and smaller-scale societies inferred the contexts of dance songs, lullabies, and healing songs, but not love songs. Within and across cohorts, inferences were mutually consistent. Further, increased linguistic or geographical proximity between listeners and singers only minimally increased the accuracy of the inferences. These results demonstrate that the behavioral contexts of three common forms of music are mutually intelligible cross-culturally and imply that musical diversity, shaped by cultural evolution, is nonetheless grounded in some universal perceptual phenomena.

Despite the global spread of intensive agriculture, many populations retained foraging or mixed subsistence strategies until well into the twentieth century. Understanding why has been a longstanding puzzle. One explanation, called the marginal habitat hypothesis, is that foraging persisted because foragers tended to live in marginal habitats generally not suited to agriculture. However, recent empirical studies have not supported this view. The alternative but untested oasis hypothesis of agricultural intensification claims that intensive agriculture developed in areas with low biodiversity and a reliable water source not reliant on local rainfall. We test both the marginal habitat and oasis hypotheses using a cross-cultural sample drawn from the 'Ethnographic atlas' (Murdock 1967 Ethnology 6 , 109-236). Our analyses provide support for both hypotheses. We found that intensive agriculture was unlikely in areas with high rainfall. Further, high biodiversity, including pathogens associated with high rainfall, appears to have limited the development of intensive agriculture. Our analyses of African societies show that tsetse flies, elephants and malaria are negatively associated with intensive agriculture, but only the effect of tsetse flies reached significance. Our results suggest that in certain ecologies intensive agriculture may be difficult or impossible to develop but that generally lower rainfall and biodiversity is favourable for its emergence. This article is part of the theme issue 'Evolutionary ecology of inequality'.

Background: Australia is yet to see widespread fentanyl-contaminated heroin, despite the established presence of fentanyl in other countries. International mortality trends alongside a local cluster of fentanyl-related deaths prompted interest in developing methods to monitor for fentanyl and other potentially harmful novel psychoactive substances (NPS) in Australia., Methods: We tested novel methods to monitor for fentanyl and other NPS. From 2017-2021, clients from supervised injecting facilities (SIFs) in Melbourne and Sydney, Australia, contributed urine screens (UDS) with BTNX Rapid Response™ fentanyl test strips (FTS) paired with surveys, and injecting equipment associated with opioid overdoses for laboratory analysis. A single site piloted drug checking using FTS with laboratory confirmation. Two workshops were conducted with SIF staff, content experts and people with lived experience to determine how results can inform practices within SIFs., Results: Of the 911 UDS with FTS conducted, less than 1% (n=8) yielded positive results that were not explained by self-reported pharmaceutical fentanyl use, with two laboratory confirmed fentanyl positive results. Injecting equipment from 59 overdoses was tested and neither fentanyl nor other NPS were identified. Drug checking with FTS (n=34) indicated the presence of fentanyl on three tests. Two specimens were subsequently sent for laboratory testing and classified as false positives as the presence of fentanyl was not confirmed. Workshop participants (n=21) felt routine monitoring with FTS currently had limited value. A process for using pre-defined signals to trigger surveillance was developed., Conclusion: The high false positive rates with FTS, relative to the small number of positive results and potential for them to undermine confidence in FTS emphasised the need for confirmatory testing. The role of routine surveillance was unclear within the current low-fentanyl context, however, a process was developed to upscale testing should signals of increased fentanyl prevalence in the Australian heroin market emerge., Competing Interests: Declarations of Interest SN and TL have received unrelated untied educational grants from Seqirus to investigate prescription opioid related harms. SN is a named investigator on a research grant from Indivior on a long-acting injectable buprenorphine implementation study. MJB volunteers for The Loop Australia (TLA), a health promotion charity working towards delivering drug-checking services in Australia that repackages and shares drug alert information with its networks. MJB also serves as the Executive Director of Bluelight.org, which hosts digital harm reduction communities where alerts about unusual drugs are often shared., (Copyright © 2023. Published by Elsevier B.V.)

Punishments for norm violations are hypothesised to be a crucial component of the maintenance of cooperation in humans but are rarely studied from a comparative perspective. We investigated the degree to which punishment systems were correlated with socioecology and cultural history. We took data from the Standard Cross-Cultural Sample database and coded ethnographic documents from a sample of 131 largely non-industrial societies. We recorded whether punishment for norm violations concerned adultery, religion, food, rape or war cowardice and whether sanctions were reputational, physical, material or execution. We used Bayesian phylogenetic regression modelling to test for culture-level covariation. We found little evidence of phylogenetic signals in evidence for punishment types, suggesting that punishment systems change relatively quickly over cultural evolutionary history. We found evidence that reputational punishment was associated with egalitarianism and the absence of food storage; material punishment was associated with the presence of food storage; physical punishment was moderately associated with greater dependence on hunting; and execution punishment was moderately associated with social stratification. Taken together, our results suggest that the role and kind of punishment vary both by the severity of the norm violation, but also by the specific socio-economic system of the society., Competing Interests: All authors declare none., (© The Author(s) 2023.)

Six fatalities have occurred from the ingestion of a combination of new psychoactive substances (NPSs), 4-fluoroamphetamine (4FA) and 2-(4-chloro-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25C-NBOMe) over a 9-month period. Four of these fatalities (one older female and three young males) were from direct adverse effects of drugs, and one each from a fall while being intoxicated and during restraint. All cases were subject to full postmortem examinations that included collection of femoral blood. The four drug-caused fatalities had postmortem blood concentrations for 4FA and 25C-NBOMe of 330-682 ng/L (median 417) and 1.4-12 ng/mL (median 4.3), respectively. The other two cases (both young males) where death was considered to have been caused indirectly by drug intoxication had 4FA and 25C-NBOMe postmortem concentrations of 21 and 123 ng/mL, and 1.8 and 4.5 ng/mL, respectively. None of these cases showed concentrations of drugs that suggested use of high recreational doses. In one drug-caused death, capsules and a brown powder obtained from the scene were found to contain a mixture of these two NPSs. With the exception of one drug-caused death, other drugs were detected; however, the effects of the two NPSs together were regarded as the primary triggers for the deaths. There were no consistent symptoms or pathology in these cases; however, agitation/aggression was observed in two cases prior to their collapse, with seizures in possibly three cases. Pulmonary and/or cerebral edema was noted in three cases. Potentially significant natural disease (a mildly enlarged heart) was only observed in one drug-caused case. These cases illustrate a possible increased risk of sudden death with this combination of drugs, both of which can elevate serotonin concentrations as well as act as strong stimulants. These cases also illustrate the difficulty in detecting NPS in cases where no prior information is available that might suggest their use., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aims: Treatment of methamphetamine dependence requires monitoring of recent use or abstinence. Self-report is commonly used for routine monitoring, but the accuracy of self-report is not established. For the treating clinician, the key accuracy statistic is the negative predictive value (NPV). The study aim was to estimate the NPV of self-reported non-use of methamphetamine compared with an oral fluid reference standard., Design, Setting and Participants: This study was a secondary (subgroup) analysis from a randomized controlled pharmacotherapy trial. Three Australian outpatient addiction services took part. Particpants were 139 people dependent on methamphetamine., Measurements: Weekly oral fluid samples over 12 weeks to determine methamphetamine (and amphetamine) concentrations were used as the reference standard. Self-report of any methamphetamine use in the previous 7 days by the time-line follow-back method was the index test. Standard diagnostic accuracy statistics were calculated for all available paired episodes (n = 1134). Three NPV values were calculated: unadjusted NPV and NPV adjusted for clustering of observations through logistic regression and generalized estimating equation (GEE). We also calculated the NPVs for a range of prevalence rates of methamphetamine use, for the calculated levels of sensitivity and specificity., Findings: Sensitivity was 96.4% [95% confidence interval (CI) = 95-97.5], specificity was 63.7% (95% CI = 57.3-69.8) and positive predictive value (PPV) was 90.8% (95% CI = 88.8-92.6). The unadjusted NPV was 82.7% (95% CI = 76.5-87.9), adjusted NPV by logistic regression 82.7% (95% CI = 73.9-91.5) and GEE 76.8% (95% CI = 66.8-86.8). At a methamphetamine use prevalence of 5%, the estimated NPV would be 99.7% (95% CI = 99.6-99.9) and at 95% prevalence, 48.2% (95% CI = 39.6-57.0)., Conclusions: Self-report of no recent methamphetamine use appears to be sufficiently accurate to be clinically useful at the expected prevalence rates of methamphetamine use in clinical treatment settings. If generalizable to clinical settings, where these tests are routinely conducted, this may permit a reduction in the frequency and cost of oral fluid assays., (© 2022 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

While some species have affiliative and even cooperative interactions between individuals of different social groups, humans are alone in having durable, positive-sum, interdependent relationships across unrelated social groups. Our capacity to have harmonious relationships that cross group boundaries is an important aspect of our species' success, allowing for the exchange of ideas, materials, and ultimately enabling cumulative cultural evolution. Knowledge about the conditions required for peaceful intergroup relationships is critical for understanding the success of our species and building a more peaceful world. How do humans create harmonious relationships across group boundaries and when did this capacity emerge in the human lineage? Answering these questions involves considering the costs and benefits of intergroup cooperation and aggression, for oneself, one's group, and one's neighbor. Taking a game theoretical perspective provides new insights into the difficulties of removing the threat of war and reveals an ironic logic to peace - the factors that enable peace also facilitate the increased scale and destructiveness of conflict. In what follows, I explore the conditions required for peace, why they are so difficult to achieve, and when we expect peace to have emerged in the human lineage. I argue that intergroup cooperation was an important component of human relationships and a selective force in our species history beginning at least 300 thousand years. But the preconditions for peace only emerged in the past 100 thousand years and likely coexisted with intermittent intergroup violence which would have also been an important and selective force in our species' history.

When interacting with infants, humans often alter their speech and song in ways thought to support communication. Theories of human child-rearing, informed by data on vocal signalling across species, predict that such alterations should appear globally. Here, we show acoustic differences between infant-directed and adult-directed vocalizations across cultures. We collected 1,615 recordings of infant- and adult-directed speech and song produced by 410 people in 21 urban, rural and small-scale societies. Infant-directedness was reliably classified from acoustic features only, with acoustic profiles of infant-directedness differing across language and music but in consistent fashions. We then studied listener sensitivity to these acoustic features. We played the recordings to 51,065 people from 187 countries, recruited via an English-language website, who guessed whether each vocalization was infant-directed. Their intuitions were more accurate than chance, predictable in part by common sets of acoustic features and robust to the effects of linguistic relatedness between vocalizer and listener. These findings inform hypotheses of the psychological functions and evolution of human communication., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Background and Aim: The current phase of the North American 'opioid crisis' is characterised by illicit fentanyl use; however, the presence of illicit fentanyl in Australia is unknown. This study aimed to monitor unintentional fentanyl consumption in Australia., Design: Rapid urine drug screens (UDS) paired with surveys conducted within supervised injecting facilities (SIFs) and confirmatory laboratory testing., Setting: Sydney and Melbourne, Australia., Participants: Clients who used heroin within the past 2 days (n = 911 tests, 2017-2021). Participants were demographically similar to the overall client base (median age 43, 72% male)., Measurements: UDS were conducted using BTNX Rapid Response fentanyl urine strip tests with cross-reactivity to numerous fentanyl analogues. Positive urine samples were analysed using liquid chromatography coupled with tandem mass spectrometry. Surveys covered past 3 day drug use and lifetime report of fentanyl in heroin., Findings: Two percent of participants reported intentional use of fentanyl, mostly through fentanyl patches. Of the 911 rapid UDS conducted, 17 (1.9%) yielded positive results. Eight of these (all from Melbourne) were not explained by survey-reported fentanyl use in the past 3 days. Of these 8 unexplained positives, confirmatory laboratory analysis was conducted on 6, with 4 deemed to be false positives, and 2 confirmed for the presence of fentanyl. This represents the first confirmation of unintended use of fentanyl type substances in this population., Conclusion: There is limited evidence of unintentional fentanyl use among people in Sydney and Melbourne, Australia who regularly inject heroin, suggesting that, currently, there is very little illicit fentanyl in Australian drug markets accessed by supervised injecting facilities attendees. This study demonstrates the feasibility of quick onsite testing to cost-effectively screen large samples for fentanyl; however, the high false positive rate emphasises the need for confirmation of positive tests through advanced analytical techniques., (© 2022 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Humans often favour ingroup members over others, a bias that drives discrimination and intergroup conflicts. Hostile relations between groups and homogeneity within groups may affect such ingroup bias. In an experiment with members of three natural groups in Ethiopia, we vary intergroup relations (neutral versus enmity) and exploit the natural variation in the homogeneity of groups (homogeneous versus heterogeneous) to identify their effect on in- and outgroup concerns. We find that ingroup bias largely manifests as positive concern for ingroup members combined with no concern for outgroup members. Enmity has no effect on ingroup bias, whereas ingroup concern is amplified in homogeneous groups. Group homogeneity, thus, is the primary driver of concerns for others in our study's context. Our results are relevant to understanding the consequences of exclusionary group identities. This article is part of the theme issue 'Intergroup conflict across taxa'.

Intergroup violence is challenging to understand: why do individuals cooperate to harm members of other groups when they themselves may be killed or injured? Despite progress in understanding the evolutionary and proximate mechanisms that underlie violence, we still have little insight into the processes that lead to the emergence of coalitionary aggression. We argue that an overlooked component is the presence of individuals who have a crucial role in initiating violence. In instigating intergroup violence, these key individuals may expect to face lower costs, receive greater benefits, or garner benefits that have a greater value to them than others. Alternatively, key individuals may be motivated by individual traits such as increased boldness, propensity for aggression or exploratory behaviour. Key individuals catalyse the emergence of coalitionary violence through one of several processes including altering the costs and benefits that accrue to others, paying a greater share of the startup costs, signalling privileged knowledge, or providing coordination, among other factors. Here we integrate diverse lines of empirical research from humans and non-human animals demonstrating that inter-individual variation is an important factor in the emergence of intergroup violence. Focusing on the role of key individuals provides new insights into how and why violence emerges. This article is part of the theme issue 'Intergroup conflict across taxa'.

For most of our species' history, humans have lived in relatively small subsistence communities, often called small-scale societies. While these groups lack centralized institutions, they can and often do maintain large-scale cooperation. Here, we explore several mechanisms promoting cooperation in small-scale societies, including (a) the development of social norms that encourage prosocial behavior, (b) reciprocal exchange relationships, (c) reputation that facilitates high-cost cooperation, (d) relational wealth, and (e) risk buffering institutions. We illustrate these with ethnographic and psychological evidence from contemporary small-scale societies. We argue that these mechanisms for cooperation helped past and present small-scale communities adapt to diverse ecological and social niches., (Copyright © 2021 Elsevier Ltd. All rights reserved.)