文档介绍：An Evolutionary Perspective on Human Fertility
Kevin MacDonald
California State University-Long Beach
This paper illustrates evolutionary approaches to population issues. Life history the-
ory is a general theoretical framework that incorporates environmental influences,
contextual influences, and heritable variation. In general, physically or psycho-
logically stressful environments delay maturation and the onset of reproductive
competence. Perceptions of scarcity also result in lower fertility by delaying repro-
duction or having fewer children—a phenomenon viewed as an adaptation to an-
cestral environments. The desire for upward social mobility is viewed as an evolved
motive disposition affecting fertility decisions. The opportunity for upward social
mobility typically results in delaying reproduction and lowering fertility in the inter-
est of increasing investment in children. Variation in life history strategies is also
influenced by ic variation, but ic variation interacts with cultural shifts in
the social control of sexual behavior. Finally, I discuss the effects of between-group
competition for resources on population issues. Immigration policy and group dif-
ferences in fertility influence political power within and between societies, often
with explosive results. Demographic expansion has often been an instrument of
petition and is an important source of conflict in the contemporary
world.
INTRODUCTION
This paper illustrates the types of contribution that an evolutionary
perspective can make to thinking about fertility and its relation to the envi-
ronment. In a very real sense fertility and especially differences in fertility
Please address correspondence to Kevin MacDonald, Department of Psychology, Califor-
nia State University-Long Beach, Long Beach, CA 90840-0901.
Population and Environment: A Journal of Interdisciplinary Studies
Volume 21, Number 2, November 1999
© 1999 Human Sciences Press, Inc. 223
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POPULAT