Personality as a state-dependent behavior: Do childhood poverty and pregnancy planning moderate the link between personality and fitness?

Abstract

One of the major evolutionary puzzles of personality is the existence of inter-individual variation in behavior. The variation in personality may be maintained by natural selection if various states moderate the link between personality and fitness - if personality traits have beneficial contribution to fitness in certain conditions but detrimental in others, the inter-individual variation in behavior will be preserved. We tested the state-dependent model of personality by examining the role of childhood poverty and pregnancy planning as states that moderate the link between six-factor personality traits and reproductive fitness (operationalized as reproductive success and the age at first reproduction). The data were collected on a large sample (N = 994), representative in regards to participants’ sex, age, and regional background in Serbia. Regression models showed that low Openness to experience is negatively associated to both fitness indicators. Furthermore, we detected interactions between states and personality in the prediction of reproductive fitness: Honesty was positively related to fitness in the favorable childhood environment, while Conscientiousness had positive associations with fitness in individuals who planned their reproduction. The data show high heuristic power of state-dependent behavior models in human personality ecology: states may maintain inter-individual variation in behavior on a population level.