Beyond cumulative risk: Distinguishing harshness and unpredictability as determinants of parenting and early life history strategy.

Abstract

Drawing on life history theory, Ellis and associates' (2009) recent across- and within-species analysis of ecological effects on reproductive development highlighted two fundamental dimensions of environmental variation and influence: harshness and unpredictability. To evaluate the unique contributions of these factors, the authors of present article examined data from a national sample 1364 mothers and their children participating in the NICHD Study of Early Child Care and Youth Development. Harshness was operationalized as income-to-needs ratio in the first 5 years of life; unpredictability was indexed by residential changes, paternal transitions, and parental job changes during this same period. Here the proposition was tested that these factors not only uniquely predict accelerated life-history strategy, operationalized in terms of sexual behavior at age 15, but that such effects are mediated by change over the early-childhood years in maternal depression and, thereby, observed maternal sensitivity in the early-elementary-school years. Structural equation modeling provided empirical support for Ellis et al.'s (2009) theorizing, calling attention once again to the contribution of evolutionary analysis to understanding contemporary human parenting and development. Implications of the findings for intervention are discussed.

Violence, Teenage Pregnancy, and Life History

“…A longitudinal study (Simpson, Griskevicius, I-Chun Kuo & Sung, in press) found that sexual and criminal behaviour at age twenty-three was predicted by the level of unpredictability experienced by 11 age five (indexed by changes to mothers residence, employment and partners). Belsky et al (2011) demonstrated similar results; focusing on sexual behaviour at age fifteen as the dependent measure.…”

Testicular volume is inversely correlated with nurturing-related brain activity in human fathers

“…If testicular volume is causal, individual differences in testes may be governed by evolved genetic influences, or they may be shaped by environmental factors analogous to the role of father absence in the timing of female menarche (36). Similar effects of early life experience on reproductive strategies have been found for males, with stress and unpredictability correlated with relatively earlier and more promiscuous sexual activity (37). It is possible, for example, that fathers in the present study who invest more in reproductive biology and less in parenting had experienced a more stressful and unpredictable childhood, or one without a father present.…”

A Life History Theory of Father Absence and Menarche: A Meta-Analysis

“…-287-moderated by lower SES or inconsistent resources (e.g., Belsky et al, 2012;Deardorff et al, 2011;Ellis et al, 2009;James-Todd, Tehranifar, Rich-Edwards, Titievsky, and Terry, 2010;Simpson, Griskevicius, Kuo, Sung, and Collins, 2012). New experimental studies have even found that simply reminding women about paternal absence or disengagement (via priming) can alter their behavior (sexual thought/permissiveness, condom use) in ways consistent with psychosocial acceleration theory (DelPriore and Hill, 2013).…”