California State University, Sacramento, researchers traced how disordered childhood social worlds in women connected to faster life history traits and greater mating effort, with those traits explaining 22.2% of the association between childhood microsystems and adult sexual behavior.
Childhood environments and strategies
Life History theory treats childhood ecology as a starting point for strategies that govern survival, mating effort, and parental effort. Mating effort involves behavior that increases access to sexual opportunities, while parental effort involves investing time and resources so children survive to reproduce.
Faster strategies align with earlier sexual debut, more short-term mating, more lifetime partners, and more offspring at younger ages. Slower strategies align with later sexual debut, safer reproductive behavior such as monogamy and contraceptive use, fewer lifetime partners, and greater parental investment.
Childhood harshness and unpredictability show up in prior work through divorce, parental job loss, frequent moves, unsafe neighborhoods, and parental substance misuse or violence. Supportive and predictable childhood environments appear with nurturing parents, stable housing, and safer neighborhoods.
Bioecological theory describes environmental layers that interact with the child over time. Microsystems contain parents, extended family, teachers, and neighbors who interact frequently and reciprocally with the child. Exosystems include factors that affect the child indirectly, such as parental employment or frequent moves.
Prior studies linked parental disengagement, father absence, and neighborhood violence to short-term mating, early sexual debut, and sexually risky behavior in adolescence and adulthood. Harsh and unpredictable environments relate to present-oriented thinking and impulsivity, which then link to risky sexual behavior. Dark Triad traits, including psychopathy and Machiavellianism, support resource control, low self-control, and mating effort, along with sexually risky behavior.
Slower profiles are associated with traits such as long-term planning, agreeableness, conscientiousness, mental and physical health, well-being, self-esteem, positive affect, and emotional intelligence.
In the study, “Using SEM to test the associations among women’s childhood ecology, adult psychosocial life history traits, and mating effort,” published in Evolution and Human Behavior, researchers used structural equation modeling to investigate how childhood microsystem and exosystem experiences, adult psychosocial traits, and mating effort fit together in women.
Participants were 875 ethnically mixed, self-identified female undergraduate college students at a university in Northern California. Ages ranged from 18 to 46 years, with a mean age of 20.55. Questionnaires included childhood ecology, adult psychosocial traits, and mating effort along with Adverse Childhood Experiences (ACE) Inventory, a 20-item checklist of hardships in childhood.
Childhood trauma, control, and partners
Correlations between microsystem indicators, faster traits, and mating effort unpacked those paths. Higher microsystem scores related to higher ACE scores, paternal and maternal disengagement, more parental cohabitation, and higher neighborhood crime. Higher microsystem scores also related to higher, faster scores and Dark Triad psychopathy, higher coercive and power-seeking resource control, higher Machiavellianism, and lower self-control.
Psychopathy showed strong links to mating effort. Higher psychopathy correlated with more lifetime sexual partners, stronger short-term mating orientation, and greater future sexual risk intentions. Machiavellianism correlated with stronger short-term mating orientation and greater future sexual risk intentions.
Self-control scores related inversely to harsh childhood conditions. Higher ACE scores and more neighborhood crime correlated with lower self-control. Lower self-control correlated with more lifetime sexual partners, more openness to casual sex, and higher future sexual risk intentions.
Resource control strategies formed another bridge. Neighborhood crime correlated with higher coercive and power-seeking resource control. Higher coercive and power-seeking scores correlated with more partners, stronger short-term mating orientation, and higher future risk intentions.
Higher neuroticism correlated with higher ACE scores, more neighborhood crime, higher father disengagement, stronger short-term mating orientation, and greater future sexual risk intentions.
Sexual start patterns
Age at first sexual encounter could not be included in the structural equation model because a substantial number of participants reported no sexual experience. 284 women reported never having sex, leaving 591 with a reported age at sexual debut. A hierarchical multiple regression used microsystem, exosystem, slower traits, and faster traits as predictors of age at sexual debut in that subgroup.
Women who grew up in more chaotic or troubled family and neighborhood environments tended to start having sex at younger ages. Broader issues such as money instability and slower life history traits did not change that pattern much.
Women with higher adversity scores, more disengaged fathers, more non-relatives living in the home, higher psychopathy, a stronger drive to control others and resources, and higher neuroticism reported younger ages at first sex.
Mothers
A total of 33 participants reported having children. For this analysis, 37 participants without children were randomly sampled to form a comparison group of 70 women.
Microsystem and exosystem scores did not significantly predict having children. Slower and faster traits did. Women in this small subgroup who showed more of the slower life history traits (things like resilience, well-being, conscientiousness, secure attachment, and grit) were more likely to have children than women with lower scores on those traits.
Women in this small subgroup who had children differed from those without children mainly in their adult traits, not in their reported childhood environments. Mothers tended to score lower on fast life history traits such as psychopathy, low self-control, and power-seeking, and higher on slow traits, while the childhood microsystem and exosystem scores did not clearly separate mothers from non-mothers.
Life history patterns and implications
Psychosocial life history traits clustered into two partly independent sets, one faster and one slower. Faster traits were linked both to harsher childhood microsystems and to higher mating efforts, many of which are explicitly risky or short term. Slower traits were linked to kinder childhood microsystems, and showed statistically non-significant associations with mating effort.
Microsystem conditions before age 10 are linked more strongly to psychosocial traits and mating effort than exosystem conditions. Childhood trauma, parental disengagement, parental cohabitation with non-kin adults, and neighborhood crime all clustered within higher microsystem scores and connected to faster traits, more partners, shorter-term mating orientation, and higher future sexual risk intentions.
Perceived resource inconsistency in the exosystem added further associations with partner counts, short-term orientation, and risk intentions.
Conclusions, limitations and open questions
Results showed that the childhood microsystem had a far greater impact than the external environment on personality development and mating strategies. Good parenting and a protective early environment that allowed security and predictability showed a trajectory of positive associations.
The cohort included only college students, a major limitation for generalizing the findings, as college attendance is conceivably a measurable outcome of Life History theory. How the findings might compare to women who did not attend college, and how this socioeconomic cutoff might alter the strength of the associations is unclear.