The evolutionary study of human family systems

Abstract

Evolutionary biologists seek to understand human behavior by postulating that many of our current social behaviors and emotions represent heritable adaptations that were selectively advantageous during our ancestral (pre-agricultural, pre-industrial) human environment. Studies of animal species that live in societies structured similarly to those of our ancestors (i.e. in multi-generational family groups) may thus provide insights into the genetically influenced behavioral predispositions that may be present in ourselves.

The evolutionary approach argues that family groupings have a biological basis. They form under particular ecological and demographic conditions when the reproduction of individuals is enhanced by prolonging the association between parents and young. Because families are comprised of close genetic relatives, a high degree of cooperation is expected between their members. Conflict is also expected, however, because the reproductive interests of parents, offspring, and other family members are rarely identical. Such conflicts are intensified in reconstituted (step) families because replacement mates (stepparents) are unrelated to offspring of the previous pairing, and extant offspring are less related to future young of the new pairing.

I develop a set of predictions specifying when, where, and between whom, conflict is expected in reconstituted family environments. After briefly documenting the robustness of this approach in explaining the behavior of non-human species, I examine its value for interpreting patterns of behavior in human stepfamilies.

I suggest that much of the increased conflict seen in modern human families is due to the recent surge in numbers of stepfamily households. Increased understanding of our behavioral predispositions can help us to design better conflict resolution strategies for human families in crisis. I offer a five point program for incorporating such knowledge into family counselling.

The evolutionary perspective does not challenge or contradict the intellectual frameworks of sociology or psychology. Rather it seeks explanations for human behavior at a different level of analysis. In doing so it provides additional information of a new dimension which should lead to a better understanding of the types and frequencies of human family dysfunction.