The dark triad (DT) traits are differentially related to psychometrically assessed life history strategy (LHS), such that psychopathy is strongly associated with a faster LHS, whereas narcissism appears to be, if anything, a slow LHS indicator. However, the research supporting these generalizations has been based largely on undergraduate samples in which LHS has been measured using the Arizona Life History Battery (ALHB; or its short version the Mini-K), an instrument that arguably lacks adequate coverage of low-extroversion content linked to a slower LHS. In this study, 929 U.S. MTurk workers completed a set of DT instruments, a 10-item Big Five Inventory, a 42-item version of the ALHB (K-SF-42), and the life history rating form (LHRF), which is less weighted toward high extroversion content than the ALHB. Factor analysis of the DT instruments yielded factors corresponding to callousness, secondary psychopathy, and socially adaptive narcissism (leadership/authority and grandiose exhibitionism). Callousness and secondary psychopathy were fast LHS indicators with respect to both LHS instruments. Socially adaptive narcissism appeared as a slow LHS indicator with respect to the K-SF-42 but as a fast LHS indicator with respect to the LHRF. Variation in extroversion accounted entirely for the K-SF-42's positive association with socially adaptive narcissism. This study suggests that narcissism's apparent status as a slow LHS indicator may be more a matter of measurement than of substance.

Although several studies have linked Life History Strategy (LHS) variation with variation in the Five Factor Model personality dimensions, no published research has explored the relationship of LHS to the HEXACO personality dimensions. The theoretically expected relationship of the HEXACO Emotionality factor to LHS is unclear. The results of two studies (N = 641) demonstrated that LHS indicators form part of a factor along with HEXACO Extraversion, Agreeableness, Conscientiousness, and (marginally) Honesty-Humility. People higher on these dimensions pursue a slower LHS. Neither Openness nor Emotionality was associated with this factor. Holding LHS constant, social involvement with kin was consistently predicted by higher Emotionality and was not consistently predicted by any other HEXACO factor. These results support a view of Emotionality as part of an LHS-independent personality dimension that influences the provision and receipt of kin altruism.

Recent research suggests the validity of the construct of Left-wing Authoritarianism (LWA). Like its well-studied parallel construct Right-wing Authoritarianism, LWA is characterized by dogmatism, punitive attitudes toward dissenters, and desire for strong authority figures. In contrast to RWA, LWA mobilizes these traits on behalf of left-wing values (e.g. anti-racism, anti-sexism, and wealth redistribution). I inductively examined the extent to which RWA and LWA predicted, in April 2020, Americans' endorsement of 19 authoritarian policies and practices intended to mitigate the effects of the COVID-19 pandemic. For 11 of these policies (e.g. abrogating the right to trial by jury for pandemic-related crimes), both RWA and LWA independently positively predicted endorsement. These findings are consistent with recent work showing psychological similarities between the two constructs.

Life history theory has generated cogent, well-supported hypotheses about individual differences in human biodemographic traits (e.g., age at sexual maturity) and psychometric traits (e.g., conscientiousness), but little is known about how variation in life history strategy (LHS) is manifest in quotidian human behavior. Here I test predicted associations between the self-report Arizona Life History Battery and frequencies of 12 behaviors observed over 72 h in 91 US college students using the Electronically Activated Recorder (EAR), a method of gathering periodic brief audio recordings as participants go about their daily lives. Bayesian multi-level aggregated binomial regression analysis found no strong associations between ALHB scores and behavior frequencies. One behavior, presence at amusement venues (bars, concerts, sports events) was weakly positively associated with ALHB-assessed slow LHS, contrary to prediction. These results may represent a challenge to the ALHB's validity. However, it remains possible that situational influences on behavior, which were not measured in the present study, moderate the relationships between psychometrically-assessed LHS and quotidian behavior.

Research on nonhuman primate personality dimensions has focused on a small number of taxa, and little of this work has focused on wild populations. We used ratings to assess personality structure in wild white-faced capuchins (Cebus capucinus) over a 9-year period, using a capuchin-specific rating instrument based partly on existing instruments. Adequate levels of interrater reliability were found for 24 of 26 items. A longitudinal analysis found that 15 of these items showed significant rank-order stability from adolescence through early adulthood. Principal components analysis revealed 5 components. Four of these components were recognizable "Big Five" dimensions: Extraversion (E), Openness (O), Neuroticism (N), and Agreeableness (A). A dimension incorporating aspects of high O and high Conscientiousness (C) was labeled Eccentricity. Every dimension except for N showed significant rank-order stability from adolescence through early adulthood. Males were more extraverted, open, neurotic, and eccentric than females, whereas females were more agreeable than males. A cross-sectional analysis revealed that openness and agreeableness declined, whereas eccentricity increased, during adulthood. The item content of capuchin Extraversion and Openness, and the existence of a distinctive Eccentricity dimension, are consistent with known characteristics of capuchin social and ecological adaptations, specifically the central roles of alliances, behavioral innovation, and social learning.

The Electronically Activated Recorder (EAR) is a method for collecting periodic brief audio snippets of participants' daily lives using a portable recording device. The EAR can potentially intrude into people's privacy, alter their natural behavior, and introduce self-selection biases greater than in other types of social science methods. Previous research (Mehl and Holleran, 2007, hereafter M&H) has shown that participant non-compliance with, and perceived obtrusiveness of, an EAR protocol are both low. However, these questions have not been addressed in jurisdictions that require the consent of all parties to recording conversations. This EAR study required participants to wear a button bearing a microphone icon and the words "This conversation may be recorded" to comply with California's all-party consent law. Results revealed self-reported obtrusiveness and non-compliance were actually lower in the present study than in the M&H study. Behaviorally assessed non-compliance did not differ between the two studies. Participants in the present study talked more about being in the study than participants in the M&H study, but such talk still comprised <2% of sampled conversations. Another potential problem with the EAR, participant self-selection bias, was addressed by comparing the EAR volunteers' HEXACO personality dimensions to a non-volunteer sample drawn from the same student population. EAR volunteers were significantly and moderately higher in Conscientiousness, and lower in Emotionality, than non-volunteers. In conclusion, the EAR method can be successfully implemented in at least one all-party consent state (California). Interested researchers are encouraged to review this procedure with their own legal counsel.

To account for the widespread human tendency to cooperate in one-shot social dilemmas, some theorists have proposed that cooperators can be reliably detected based on ethological displays that are difficult to fake. Experimental findings have supported the view that cooperators can be distinguished from defectors based on "thin slices" of behavior, but the relevant cues have remained elusive, and the role of the judge's perspective remains unclear. In this study, we followed triadic conversations among unacquainted same-sex college students with unannounced dyadic one-shot prisoner's dilemmas, and asked participants to guess the PD decisions made toward them and among the other two participants. Two other sets of participants guessed the PD decisions after viewing videotape of the conversations, either with foreknowledge (informed), or without foreknowledge (naïve), of the post-conversation PD. Only naïve video viewers approached better-than-chance prediction accuracy, and they were significantly accurate at predicting the PD decisions of only opposite-sexed conversation participants. Four ethological displays recently proposed to cue defection in one-shot social dilemmas (arms crossed, lean back, hand touch, and face touch) failed to predict either actual defection or guesses of defection by any category of observer. Our results cast doubt on the role of "greenbeard" signals in the evolution of human prosociality, although they suggest that eavesdropping may be more informative about others' cooperative propensities than direct interaction.

During conversation, interlocutors coordinate their behavior on many levels. Two distinct forms of behavioral coordination have been empirically linked with affiliation and cooperation during or following face-to-face interaction: behavior matching and interpersonal synchrony. Only the latter form constitutes behavioral entrainment involving a coupling between independent oscillators. We present the first study of the association between spontaneously occurring behavioral coordination and post-interaction economic game play. Triads of same-sexed strangers conversed for 10. min, after which each participant played an unannounced one-shot prisoner's dilemma (PD) toward each co-participant. When dyads had higher language style matching scores (LSM: Gonzales, A.L., Hancock, J.T., & Pennebaker, J.W. (2010). Language style matching as a predictor of social dynamics in small groups. Communication Research, 31, 3-19), the individuals evaluated each other more positively, but they were no more likely to cooperate in the PD. However, when dyads' speech rates (mean syllable duration) converged more strongly from the beginning to the end of the conversation, they were more likely to cooperate in the PD, despite no effect on interpersonal evaluations. Speech rate convergence, a form of rhythmic entrainment, could benefit interlocutors by mutually reducing cognitive processing during interaction. We suggest that spontaneous, temporally based behavioral coordination might facilitate prosocial behavior when the joint cooperative effort is itself perceived as a form of coordination. © 2013 Elsevier Inc.