Quantity-Quality Trade-Offs May Partially Explain Inter-Individual Variation in Psychopathy

Validating the Revised Mating Effort Questionnaire

The mating effort questionnaire (MEQ) is a multi-dimensional self-report instrument that captures factors reflecting individual effort in upgrading from a current partner, investment in a current partner, and mate seeking when not romantically paired. In the current studies, we sought to revise the MEQ so that it distinguishes among two facets of mate seeking-mate locating and mate attracting-to enable a more nuanced measurement and understanding of individual mating effort. Moreover, we developed additional items to better measure partner investment. In total, the number of items was increased from 12 to 26. In Study 1, exploratory factor analysis revealed that a four-factor solution, reflecting partner upgrading, mate locating, mate attracting, and partner investment, yielded the best fit. In Study 2, this structure was replicated using confirmatory factor analysis in an independent sample. Based on extant studies documenting the relationships between psychopathy, short-term mating effort, and sexual risk taking, a structural equation model (SEM) indicated that trait psychopathy positively predicted mate locating, mate attracting, and partner upgrading and negatively predicted partner investment. A separate SEM showed that partner upgrading positively predicted risky sexual behaviors, while partner upgrading and mate locating positively predicted acceptance of cosmetic surgery.

The evolution of personality disorders: A review of proposals

Personality disorders (PDs) are currently considered dysfunctions. However, personality differences are older than humanity and are ubiquitous in nature, from insects to higher primates. This suggests that a number of evolutionary mechanisms-other than dysfunctions-may be able to maintain stable behavioral variation in the gene pool. First of all, apparently maladaptive traits may actually improve fitness by enabling better survival or successful mating or reproduction, as exemplified by neuroticism, psychopathy, and narcissism. Furthermore, some PDs may harm important biological goals while facilitating others, or may be globally beneficial or detrimental depending on environmental circumstances or body condition. Alternatively, certain traits may form part of life history strategies: Coordinated suites of morphological, physiological and behavioral characters that optimize fitness through alternative routes and respond to selection as a whole. Still others may be vestigial adaptations that are no longer beneficial in present times. Finally, variation may be adaptative in and by itself, as it reduces competition for finite resources. These and other evolutionary mechanisms are reviewed and illustrated through human and non-human examples. Evolutionary theory is the best-substantiated explanatory framework across the life sciences, and may shed light on the question of why harmful personalities exist at all.

Is it good to be bad? An evolutionary analysis of the adaptive potential of psychopathic traits

Although psychopathy is widely conceptualised as a mental disorder, some researchers question the maladaptive nature of psychopathy, and argue that it might be advantageous from an evolutionary point of view. According to this view, psychopathy can be seen as an evolutionary adaptative strategy that relies on deception and manipulation to gain short-term reproductive benefits. Psychopathy is also identified as a fast life strategy in response to early life stress and an adaptation to harsh environments. This paper investigates the evidence that psychopathic traits are adaptive, while also addressing the limitations of current evolutionary models of psychopathy based on frequency-dependent selection and life history theory. We review recent studies on the fitness correlates of psychopathy and find that psychopathic traits present potential adaptive trade-offs between fertility and mortality, and offspring quantity and quality. On a proximate level, individual differences in stress reactivity and environmental risk factors in early development predispose to psychopathy through gene-environment interactions. We propose that environmental, developmental, social and cultural factors can mediate the relationship between psychopathic traits and fitness and therefore should be considered to make accurate predictions on the adaptive potential of psychopathy. We end by outlining gaps in the literature and making recommendations for future evolutionary research on psychopathy.

A Double-Track Pathway to Fast Strategy in Humans and Its Personality Correlates

The fast-slow paradigm of life history (LH) focuses on how individuals grow, mate, and reproduce at different paces. This paradigm can contribute substantially to the field of personality and individual differences provided that it is more strictly based on evolutionary biology than it has been so far. Our study tested the existence of a fast-slow continuum underlying indicators of reproductive effort-offspring output, age at first reproduction, number and stability of sexual partners-in 1,043 outpatients with healthy to severely disordered personalities. Two axes emerged reflecting a double-track pathway to fast strategy, based on restricted and unrestricted sociosexual strategies. When rotated, the fast-slow and sociosexuality axes turned out to be independent. Contrary to expectations, neither somatic effort-investment in status, material resources, social capital, and maintenance/survival-was aligned with reproductive effort, nor a clear tradeoff between current and future reproduction was evident. Finally, we examined the association of LH axes with seven high-order personality pathology traits: negative emotionality, impulsivity, antagonism, persistence-compulsivity, subordination, and psychoticism. Persistent and disinhibited subjects appeared as fast-restricted and fast-unrestricted strategists, respectively, whereas asocial subjects were slow strategists. Associations of LH traits with each other and with personality are far more complex than usually assumed in evolutionary psychology.

Longitudinal Associations Between Primary and Secondary Psychopathic Traits, Delinquency, and Current Dating Status in Adolescence

Many have examined the desirability and mate competition tactics of adults higher on psychopathy using cross-sectional data, but few have studied the longitudinal associations between the lower-order factors of psychopathy (e.g., primary and secondary psychopathy) with indices of mating behavior in adolescents. More work is also needed to unravel how psychopathic youth outcompete rivals for mates. Delinquency has long been associated with dating and sexual behavior in adolescents, which may help to explain the competitive success of youth higher in psychopathic traits in vying for mates. We used cross-lagged panel modeling with three waves of data from a randomly drawn sample of 514 Canadian adolescents who provided annual self-reports of primary and secondary psychopathy, delinquency, and dating involvement from Grades 10 to 12 (15-18 years of age). Constructs were temporally stable. Secondary psychopathy and delinquency had positive within-time correlations with current dating status in Grade 10. A cross-lagged pathway from delinquency to dating involvement was supported from Grade 10 to 11, which replicated from Grade 11 to 12. However, this effect was specific to boys and not girls. An indirect effect also emerged whereby secondary psychopathy in Grade 10 increased the likelihood of being in a dating relationship in Grade 12 via heightened delinquency in Grade 11.

Long-term mating positively predicts both reproductive fitness and parental investment

Empirical data on the relations between mating and reproductive success are rare for humans, especially for industrial and post-industrial populations. Existing data show that mating (and especially long-term mating) can be beneficial for fitness, especially that of males. This finding is in line with the hypothesis of sexual selection operating in human populations. The present research expands on previous studies by: 1) analysing additional fitness indicators, including having children with different partners; 2) including parental investment in the analysis as another important marker of sexual selection; 3) analysing several mediators between mating, reproductive fitness and parental investment, i.e. age of first and last reproduction and desired number of children. The data were obtained in 2019 from a sample of parents living in Serbia (N=497). The findings showed that long-term mating (duration of longest partner relationship) was positively related to parental investment and number of offspring and grand-offspring. Furthermore, the link between long-term mating and reproductive success was completely mediated by the age of first reproduction and desired number of children. Short-term mating (number of sexual partners) was marginally positively related to the number of children participants had with different partners and negatively related to parental investment. No sex differences in the link between mating, fitness and parental investment were detected. In general, the signatures of sexual selection were weak in the present data, but those that were detected were in line with sexual selection theory. The present findings provide a deeper insight into the adaptive function of mating and also the mechanism of how mating is beneficial for fitness.