The effect of early-life harshness and unpredictability on intimate partner violence in adulthood: A life history perspective

According to life history theory, exposure to harshness and/or unpredictability early in life should promote a fast life history strategy. Such a strategy entails, among other traits, elevated aggression and impaired relationship functioning. While detrimental under safe and stable conditions, these characteristics become more evolutionary adaptive in a harsh and/or ever-changing environment in which risks are uncertain and the future is difficult to predict. Hence, individuals who experienced harshness and/or unpredictability in their early home environment should grow up to have more conflictual relationships and be at greater risk for experiencing or perpetrating intimate partner violence (IPV). We tested this hypothesis on 179 participants in the Minnesota Longitudinal Study of Risk and Adaptation, an ongoing prospective longitudinal study that has followed individuals from before they were born into adulthood. IPV was assessed by the Conflict Tactics Scale at ages 23, 26, and 32. As expected, experiencing more unpredictability during the first 5 years of life (indexed by frequent changes in parents’ employment status, cohabitation status, and residence) prospectively predicted both perpetrating and being the victim of IPV between ages 20 and 32. Experiencing harshness during the first 5 years of life (indexed by low socioeconomic status) only predicted being the victim of IPV. The early unpredictability effect on IPV perpetration was partially mediated by having more conflictual friendships during adolescence (assessed by a coder-rated friendship interview at age 16). These findings highlight the roles of early-life harshness and unpredictability both in promoting interpersonal conflict and violence and in impairing the capacity of individuals to maintain satisfying romantic relationships.