The parental investment model and minimum mate choice criteria in humans

Trivers' parental investment model states that individuals facinghigher levels of parental investment will become increasinglychoosy in their choice of mates. For humans, this leads to twopredictions. First, both males and females will be choosierin relationships more likely to lead to the production of children.Second, females will be choosier than are males, because theirminimum risk of parental investment is higher. Previous studiesof human mate choice found support for these predictions, withone curious exception: male choosiness was lower for short-termsexual relationships involving no relationship commitment (one-nightstands) than for short-term relationships involving no sexualactivity (single dates). Because the risk of parental investmentwould be higher in a one-night stand, this suggests that truerisk of parental investment was not the underlying factor governingchoosiness levels, either because study subjects assigned differentlevels of sexual activity to the relationships than were intendedby the investigators of the study or because perceived riskis more important in human mate choice than real risk. To confirmthat male/female differences in choosiness criteria exist inhumans, and to evaluate the effect that different expected levelsof real or perceived parental investment may have on choosiness,we studied mate choosiness in the context of five types of relationshipsthat reflected explicitly defined, increasing levels of riskof parental investment for both males and females. The subjectswere 468 undergraduate students, mostly between the ages of18–24. By using questionnaires, male and female participantsrated their minimum requirements in a potential mate for 29personal characteristics with respect to level of relationship.Our results confirm the major predictions of the parental investmentmodel for humans but suggest that sex differences in choosinessare better explained by perceived rather than real risk of parentalinvestment.