The Life History Narrative: How Early Events and Psychological Processes Relate to Biodemographic Measures of Life History

Abstract

The aim of this project is to examine the relationships between two approaches to the measurement of life history strategies. The traditional method, termed here the biodemographic approach, measures developmental characteristics like birthweight, gestation length, inter-birth intervals, pubertal timing, and sexual debut. The alternative method under exploration, termed here the psychological approach, measures a suite of cognitive and behavioral traits such as altruism, sociosexual orientation, personality, mutualism, familial relationships, and religiosity. Although both approaches are supported by a large body of literature, they remain relatively segregated. This study draws inspiration from both views, integrating measures that assess developmental milestones, including birthweight, prematurity, pubertal timing, and onset of sexual behavior, as well as psychological life history measures such as the Mini-K and a personality inventory. Drawing on previous theoretical work on the fundamental dimensions of environmental risk, these measures are tested in conjunction with several scales assessing the stability of early environmental conditions, including both "event-based" measures that are defined with an external referent, and measures of internal schemata, or the predicted psychological sequelae of early events. The data are tested in a three-part sequence, beginning with the measurement models under investigation, proceeding to an exploratory analysis of the causal network, and finishing with a cross-validation of the structural model on a new sample. The findings point to exciting new directions for future researchers who seek to integrate the two perspectives.