Reproductive Failure among Women: Pathology or Adaptation?

Abstract

A wide variety of mammals suppress their reproduction in response to cues reflecting environmental harshness, or poor physical condition of themselves or their developing conceptus. Such reproductive suppression may take the form of delayed sexual maturation, ovulatory or implantational failure, spontaneous abortion, abandonment, neglect, abuse, or infanticide. The literature we review suggests that reproductive suppression is equally prevalent among humans. However, while such phenomena among non-human mammals are commonly viewed as an adaptive response to poor reproductive conditions, similar phenomena among humans are often viewed as pathological. This paper describes a model for the evolution of reproductive ‘failure' among female mammals, termed the Reproductive Suppresion Model (RSM). It then reviews the literature on psychosocial stress and reproductive outcome among women, showing where these data are consistent with expectations from the RSM. Some biomedical studies of reproductive failure among humans that are consistent with the RSM are described as well, as are data on conscious decisions to contracept and electively terminate pregnancy. The paper then turns to approaches that address the evolution of social systems, in general, showing how questions generated from such models might also be applied to studies of psychosocial dynamics and reproductive outcomes among humans. Means we are using to acquire the appropriate data to address such questions among contemporary human populations are described, as are implications of this overall approach to biomedical practices.