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Open-source software improves the reproducibility of scient ific research. Because existing open-source tools often do not offer dedicated support for longit udinal data collection on phones and computers, we built formr, a study framework that enables researchers to conduct both simple s urveys and more intricate Studies. With automated email and text message reminders that can be sent according to any schedule, longitudinal and experience-sampling studies become easy to implement. By integrating a web-based application programming interf ace for the statistical pro gramming language R via OpenCPU, formr allows researchers to use a familiar programming language to enable complex features. These can range from adaptive testing, to graphical and interactive feedback, to integration with non-survey data sources such as self-trackers or online s ocial network data. Here we showcase three studies created in formr: a study of couples with dyadic feedback; a longitudinal study over months, which included social networks and peer and partner ratings; and a diary study with daily invitations sent out by text message and email and extensive feedback on intraindividual patterns.
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The current project measures personality across cultures, for the first time using a forced-choice (or idiographic) assessment instrument - the California Adult Q-set (CAQ). Correlations among the average personality profiles across 13 countries (total N = 2,370) ranged from r = .69 to r = .98. The most similar averaged personality profiles were between USA/Canada; the least similar were South Korea/Russia/Poland and China/Russia. The Czech Republic had the most homogeneous personality descriptions and South Korea had the least. In further analyses, country differences in CAQ-derived Big Five scores were compared to results obtained from previous research using nomothetic Likert scales (i.e., the NEO; the BFI). The Big Five templates produced generally similar findings to previous research com-paring the Big Five across countries using Likert-type methods.
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Women's mating psychology may have evolved to track reproductive conditions, including conception risk, across and between ovulatory cycles. Alternatively, within-woman correlations between mating psychology and ovarian hormones may be byproducts of between-women relationships. Here, we examined associations between steroid hormones and two facets of sexual psychology with putatively different adaptive functions, sociosexual orientation and general sexual desire, in a sample of naturally cycling women (NC; n = 348, 87 of whom completed 2 sessions) and hormonally contracepting women (HC; n = 266, 65 of whom completed 2 sessions). Across two sessions, increases in estradiol predicted elevated sociosexual desire in NC women, and this relationship was stronger in women whose progesterone simultaneously decreased across sessions. Changes in hormones were not associated with changes in general sexual desire. Between-subjects differences in testosterone robustly, positively predicted sociosexuality and general sexual desire among NC women. Hormones were not consistently related to changes or differences in sexual psychology among HC women. The present results are consistent with testosterone contributing to individual differences, or modulating relatively long-term changes, in women's mating psychology. Further, our within-woman findings are consistent with the hypothesis that shifts in women's mating psychology may function to secure genetic benefits, and that these shifts are not byproducts of between-women associations.
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As is the case for humans, it has long been thought that nonhuman primates can be described in terms of their personality. Scientific observations that support this view include the presence of individual differences in social behavior and that they are relatively stable throughout life. Consequently, individuals are constrained in their behavioral flexibility when dealing with various environmental challenges. Still, the variation among individuals during development suggests that the environment influences how primates behave. Research in fields including psychology, behavior genetics, and behavioral ecology have tried to identify the mechanisms responsible for this interplay of behavioral stability and change. In this review we integrate theories and findings from research on humans and nonhuman primates that highlight how and to what extent genetic and environmental contributions shape the development of social behavior. To do so we first provide an overview and define what is meant by mean level and rank-order change of behavior. We then review explanations of behavioral stability and change, focusing on the role of genetic effects, how environmental circumstances influence behavioral variation throughout development, and how genetic and environmental influences may interact to produce this variation. Finally, we point to future research directions that could help us to further understand the development of social behavior in primates from within a behavior genetics framework.
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The theory of facultative calibration, which explains personality differences as responses to variation in other phenotypic traits of individuals, received mixed results throughout the last years. Whereas there is strong evidence that individual differences in human behavior are correlated with the self-perception of other traits, it still needs to be questioned whether they are also adjusted to objective differences in body condition (i.e. formidability). In two independent studies (N 1 = 119 men and 124 women, N 2 = 165 men) we tested hypotheses of facultative personality calibration in an integrative way, assessing various outcomes of previous studies in the same samples (including Anger Proneness, Extraversion, Neuroticism, Narcissism, Shyness, Vengefulness, and Sociosexual Orientation). Formidability was derived from assessments of physical strength and various anthropometric measures from full-body 3D scans and paired with measures of self-perceived and other-rated physical attractiveness (based on rotating morphometric 3D body models and facial photographs). We could replicate positive correlations with self-perceived attractiveness across outcomes, though these were not corroborated by more objective assessments of attractiveness: an effect of other-rated attractiveness was clearly not supported in our results for either sex, regardless of the personality outcome. Anthropometric measures and physical strength were also largely unrelated to personality, with the exception of Extraversion, Utility of Personal Aggression, and Sociosexual Orientation. While the two samples differed in their results for domain-level Extraversion, at least the Extraversion facets Activity and Assertiveness were related to strength and masculinity in men. For Sociosexual Orientation the results of our two samples varied more substantially, a positive association was only present in Study 2. Future studies need to clarify whether formidability, potentially an indicator of genetic quality for males, enhances their orientation and success in short-term mating. Furthermore we propose longitudinal twin-difference studies as means to evaluate the theory of personality recalibration in a more controlled manner.
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Objectives The dual-hormone hypothesis suggests that associations of testosterone (T) with certain behavioral tendencies are stronger when cortisol (C) levels are low simultaneously. A range of studies provided supporting evidence for TxC interaction effects, for example on dominance and risk-taking behaviors. However, concerning perceptions of facial characteristics the evidence is mixed, with a recent study reporting a positive association between perceived facial dominance and T among men with higher C. Methods We sought to further examine links of observer-rated facial attractiveness, dominance and health (based on photographs of N = 165 men) with baseline T, competition-induced T reactivity, and their interaction with baseline C. Results There was some evidence that baseline T and the interaction of T reactivity with baseline C positively predicted facial dominance, however these were not robust when including control variables. Conclusions Since no effects were found for perceived attractiveness and health, our results suggest that associations of perceived facial characteristics with baseline T, T reactivity and their interactions with baseline C are rather weak.
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Objectives Facial masculinity, as for example measured by the facial width-to-height ratio (fWHR) or the global facial masculinity index, has been associated with a vast range of behavioural traits, including dominance and aggression. Further, facial masculinity is thought to be influenced by testosterone (T) levels as an underlying mechanism. However, a recent meta-analysis on fWHR and T levels provided non-significant associations in men, which we wanted to examine further in men and additionally in women. Methods We examined whether fWHR and global facial masculinity are positively associated with salivary baseline T and T reactivity in 140 men (age 18-34 years), as well as with salivary baseline T and hair T concentrations in 151 women (age 18-35 years). Results No associations of salivary baseline T, T reactivity or hair T levels with fWHR or global facial masculinity were observed. Additional analyses revealed sex differences in sexual dimorphism in fWHR and global facial masculinity: men had generally higher global facial masculinity compared to women, but unexpectedly a lower fWHR. Conclusions Overall, our results provide further evidence that neither fWHR nor global facial masculinity are related to T levels and question earlier findings on male-biased sexual dimorphism in fWHR.
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Event history calendars (EHCs) are popular tools for retrospective data collection. Originally conceptualized as face-to-face interviews, EHCs contain various questions about the respondents’ autobiography in order to use their experiences as cues to facilitate remembering. For relationship researchers, EHCs are particularly valuable when trying to reconstruct the relational past of individuals. However, while many studies are conducted online nowadays, no online adaptation of the EHC is available yet. In this tutorial, we provide detailed instructions on how to implement an online EHC for the reconstruction of romantic relationship histories within the open source framework formr. We exemplify on ways to customize the online EHC and provide a template for researchers to adapt the tool for their own purposes.
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Are estrous mate preference shifts robust? This question is the subject of controversy within human evolutionary sciences. For nearly two decades, mate preference shifts across the ovulatory cycle were considered an important feature of human sexual selection, directing women’s attention towards mates with indicators of “good genes” in their fertile phase, when conception is possible. However, several recent studies on masculine faces, bodies or behaviors have failed to find evidence supporting this account, known as the good genes ovulatory shift hypothesis. Furthermore, evidence that preferences for masculine characteristics in men’s voices are related to women’s cycle phase and hormonal status is still equivocal. Here, we report two independent within-subject studies from different labs with large sample sizes (N = 202 tested twice in Study 1; N = 157 tested four times in Study 2) investigating cycle shifts in women’s preferences for masculine voices. In both studies, hormonal status was assessed directly using salivary assays of steroid hormones. We did not find evidence for effects of cycle phase, conception risk or steroid hormone levels on women’s preferences for masculine voices. Rather, Study 2 suggests cycle shifts in women’s attraction to men’s voices regardless of masculine characteristics, though Study 1 provided only partly evidence for such attraction shifts. Women’s relationship status and self-reported stress did not moderate these findings, and the hormonal pattern that influences these shifts remains somewhat unclear. We consider how future work can clarify the mechanisms underlying psychological changes across the ovulatory cycle.
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Objective: Mean speed of responding is the most commonly used measure in the assessment of reaction time (RT). An alternative measure is intraindividual variability (IIV): the inconsistency of responding across multiple trials of a test. IIV has been suggested as an important indicator of central nervous system functioning, and as such, there has been increasing interest in the associations between IIV and brain imaging metrics. Results however, have been inconsistent. The present seeks to provide a comprehensive evaluation of the associations between a variety of measures of brain white matter integrity and individual differences in choice RT (CRT) IIV. Method: MRI brain scans of members of the Lothian Birth Cohort 1936 were assessed to obtain measures of the volume and severity of white matter hyperintensities, and the integrity of brain white matter tracts. CRT was assessed with a 4 CRT task on a separate occasion. Data were analyzed using multiple regression (N range = 358–670). Results: Greater volume of hyperintensities and more severe hyperintensities in frontal regions were associated with higher CRT IIV. White matter tract integrity, as assessed by both fractional anisotropy and mean diffusivity, showed the smallest effect sizes in associations with CRT IIV. Associations with hyperintensities were attenuated and no longer significant after controlling for M CRT. Conclusions: Taken together, the results of the present study suggested that IIV was not incrementally predictive of white matter integrity over mean speed. This is in contrast to previous reports, and highlights the need for further study.
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Previous research reported ovulatory changes in women’s appearance, mate preferences, extra- and in-pair sexual desire and behaviour, but has been criticised for small sample sizes, inappropriate designs, and undisclosed flexibility in analyses. In the present study, we sought to address these criticisms by preregistering our hypotheses and analysis plan and by collecting a large diary sample. We gathered over 26 thousand usable online self-reports in a diary format from 1043 women, of which 421 were naturally cycling. We inferred the fertile period from menstrual onset reports. We used hormonal contraceptive users as a quasi-control group, as they experience menstruation, but not ovulation. We probed our results for robustness to different approaches (including different fertility estimates, different exclusion criteria, adjusting for potential confounds, moderation by methodological factors). We found robust evidence supporting previously reported ovulatory increases in extra-pair desire and behaviour, in-pair desire, and self-perceived desirability, as well as no unexpected associations. Yet, we did not find predicted effects on partner mate retention behaviour, clothing choices, or narcissism. Contrary to some of the earlier literature, partners’ sexual attractiveness did not moderate the cycle shifts. Taken together, the replicability of the existing literature on ovulatory changes was mixed. We conclude with simulation-based recommendations for reading the past literature and for designing future large-scale preregistered within-subject studies to understand ovulatory cycle changes and the effects of hormonal contraception. Interindividual differences in the size of ovulatory changes emerge as an important area for further study.
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Recent evidence suggests that in sexual selection on human males, intrasexual competition plays a larger role than female choice. In a sample of men (N = 164), we sought to provide further evidence on the effects of men’s physical dominance and sexual attractiveness on mating success and hence in sexual selection. Objective measures and subjective ratings of male sexually dimorphic traits purportedly under sexual selection (height, vocal and facial masculinity, upper body size from 3D scans, physical strength, and baseline testosterone) and observer perceptions of physical dominance and sexual attractiveness based on self-presentation video recordings were assessed and associated with mating success (sociosexual behaviour and number of potential conceptions) in a partly longitudinal design. Results from structural equation models and selection analyses revealed that physical dominance, but not sexual attractiveness, predicted mating success. Physical dominance mediated associations of upper body size, physical strength, as well as vocal and facial physical dominance and attractiveness with mating success. These findings thus suggest a greater importance of intrasexual competition than female choice in human male sexual selection.
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Increases in men’s testosterone (T) levels after intrasexual competitions and exposure to females facilitate competitive and courtship behaviours, suggesting T reactivity should affect relevant personality state changes. How exactly T reactivity, also under potential buffering effects of cortisol (C), relates to personality state changes is unclear. In a preregistered study, we aimed at inducing T increases in young men (N = 165) through dyadic intrasexual competitions while exposed to a female experimenter. We investigated self-reported and video-based observer-rated personality state changes, captured by the interpersonal circumplex and social impressions, in relation to hormonal levels. Results revealed increases in self-reported competitiveness and observer-rated self-assurance, relative to a control group, moderated by T reactivity and partly by TxC interactions, providing insights into hormone-personality response-link.
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The existence of ovulatory cycle shifts in women’s mate preferences has been discussed controversially. There is evidence that naturally cycling women in their fertile phase, compared to their luteal phase, evaluate specific behavioral cues in men as more attractive for sexual relationships. However, recent research has cast doubt on these findings. We addressed this debate in a large, pre-registered within-subject study including salivary hormone measures and luteinizing hormone tests. One-hundred-fifty-seven female participants rated natural videos of 70 men in dyadic intersexual interactions on sexual and long-term attractiveness. Multilevel comparisons across two ovulatory cycles indicated that women’s mate preferences for men’s behaviors did not shift across the cycle, neither for competitive, nor for courtship behavior. Hormone levels and relationship status did not affect these results. Hormonal mechanisms and implications for estrus theories are discussed.
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Although empirical research has investigated what we ideally seek in a romantic partner for decades, the crucial question of whether ideal partner preferences actually guide our mating decisions in real life has remained largely unanswered. One reason for this is the lack of designs that assess individuals’ ideal partner preferences before entering a relationship and then follow up on them over an extended period. In the Göttingen Mate Choice Study (GMCS), a preregistered, large-scale online study, we employed such a naturalistic prospective design. We investigated partner preferences across four preference domains in a large sample of predominantly heterosexual singles (N = 763, aged 18-40 years) and tracked these individuals across a period of five months upon a possible transition into romantic relationships. Attesting to their predictive validity, partner preferences prospectively predicted the characteristics of later partners. This was equally true for both sexes, except for vitality-attractiveness where men’s preferences were more predictive of their later partners’ standing on this dimension than women’s. Self-perceived mate value did not moderate the preference-partner characteristics relations. Preferences proved to be relatively stable across the five months interval, yet were less stable for those who entered a relationship. Subgroup analyses using a newly developed indicator of preference adjustment towards (vs. away from) partner characteristics revealed that participants adjusted their preferences downwards when partners fell short of initial preferences, but showed no consistent adjustment when partners exceeded them. Results and implications are discussed against the background of ongoing controversies in mate choice and romantic relationship research.
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Relationship satisfaction is the most researched aspect in the study of couple relationships. Very broadly, it refers to a person’s overall evaluation of his or her relationship. This may entail, for example, the degree to which one’s needs and desires for love, support, and security or one’s expectations are met. Researchers are far from consensus regarding relationship satisfaction’s conceptualization. While some have advocated a unidimensional view of global relationship satisfaction, other researchers have called for multidimensional views (such as multiple satisfactions with different aspects of the relationship or different components of relationship quality). This is also mirrored in the variety of satisfaction measures employed in the study of couple relationships.
