No abstract

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.

This Campbell systematic review assesses the direct and indirect benefits of public police interventions that use procedurally just dialogue. The review summarises findings from 30 studies conducted in Australia, the USA and England. The participants were individuals (citizen, victim, offender etc.), groups (e.g. community) and third parties (e.g. religious advisors). Police‐led interventions specifically aimed at increasing legitimacy have a significant impact on public satisfaction with and confidence in the police. Such interventions are also associated with significantly increased public compliance/cooperation, procedural justice (fairness, neutrality, etc.) and legitimacy (obligation to obey police/law). Interventions also had a minor effect on reoffending. Executive Summary/Abstract BACKGROUNDPolice require voluntary cooperation from the general public to be effective in controlling crime and maintaining order. Research shows that citizens are more likely to comply and cooperate with police and obey the law when they view the police as legitimate. The most common pathway that the police use to increase citizen perceptions of legitimacy is through the use of procedural justice. Procedural justice, as described in the literature, comprises four essential components. These components are citizen participation in the proceedings prior to an authority reaching a decision (or voice), perceived neutrality of the authority in making the decision, whether or not the authority showed dignity and respect toward citizens throughout the interaction, and whether or not the authority conveyed trustworthy motives.Police departments throughout the world are implicitly and explicitly weaving the dialogue of these four principles of procedural justice (treating people with dignity and respect, giving citizens “voice” during encounters, being neutral in decision making, and conveying trustworthy motives) into their operational policing programs and interventions. OBJECTIVESThis review synthesizes published and unpublished empirical evidence on the impact of interventions led by the public police to enhance citizen perceptions of police legitimacy. Our objective is to provide a systematic review of the direct and indirect benefits of policing approaches that foster legitimacy in policing that either report an explicit statement that the intervention sought to increase legitimacy or report that there was an application of at least one of the principles of procedural justice: participation, neutrality, dignity/respect, and trustworthy motives. SEARCH STRATEGYStudies were identified using six electronic databases (CSA, Informit, Ingenta Connect, Ovid, Proquest and Web of Knowledge) and two library catalogues (National Police Library and the Cambridge University Library and dependent libraries). We also searched the reference list of each eligible study, and reviewed the biographies and publication lists of influential authors in the field of procedural justice and police legitimacy, to determine if there were any relevant studies ...

Systematic reviews and meta-analyses are used to combine results across studies to determine an overall effect. Meta-analysis is especially useful for combining evidence to inform social policy, but meta-analyses of applied social science research may encounter practical issues arising from the nature of the research domain. The current paper identifies potential resolutions to four issues that may be encountered in systematic reviews and meta-analyses in social research. The four issues are: scoping and targeting research questions appropriate for meta-analysis; selecting eligibility criteria where primary studies vary in research design and choice of outcome measures; dealing with inconsistent reporting in primary studies; and identifying sources of heterogeneity with multiple confounded moderators. The paper presents an overview of each issue with a review of potential resolutions, identified from similar issues encountered in meta-analysis in medical and biological sciences. The discussion aims to share and improve methodology in systematic reviews and meta-analysis by promoting cross-disciplinary communication, that is, to encourage ‘viewing through different lenses’.

Females can benefit from mate choice for male traits (e.g. sexual ornaments or body condition) that reliably signal the effect that mating will have on mean offspring fitness. These male-derived benefits can be due to material and/or genetic effects. The latter include an increase in the attractiveness, hence likely mating success, of sons. Females can potentially enhance any sex-biased benefits of mating with certain males by adjusting the offspring sex ratio depending on their mate's phenotype. One hypothesis is that females should produce mainly sons when mating with more attractive or higher quality males. Here we perform a meta-analysis of the empirical literature that has accumulated to test this hypothesis. The mean effect size was small (r = 0.064-0.095; i.e. explaining <1% of variation in offspring sex ratios) but statistically significant in the predicted direction. It was, however, not robust to correction for an apparent publication bias towards significantly positive results. We also examined the strength of the relationship using different indices of male attractiveness/quality that have been invoked by researchers (ornaments, behavioural displays, female preference scores, body condition, male age, body size, and whether a male is a within-pair or extra-pair mate). Only ornamentation and body size significantly predicted the proportion of sons produced. We obtained similar results regardless of whether we ran a standard random-effects meta-analysis, or a multi-level, Bayesian model that included a correction for phylogenetic non-independence. A moderate proportion of the variance in effect sizes (51.6-56.2%) was due to variation that was not attributable to sampling error (i.e. sample size). Much of this non-sampling error variance was not attributable to phylogenetic effects or high repeatability of effect sizes among species. It was approximately equally attributable to differences (occurring for unknown reasons) in effect sizes among and within studies (25.3, 22.9% of the total variance). There were no significant effects of year of publication or two aspects of study design (experimental/observational or field/laboratory) on reported effect sizes. We discuss various practical reasons and theoretical arguments as to why small effect sizes should be expected, and why there might be relatively high variation among studies. Currently, there are no species where replicated, experimental studies show that mothers adjust the offspring sex ratio in response to a generally preferred male phenotype. Ultimately, we need more experimental studies that test directly whether females produce more sons when mated to relatively more attractive males, and that provide the requisite evidence that their sons have higher mean fitness than their daughters.