Jealousy in Sexual and Emotional Infidelity: An Alternative to the Evolutionary Explanation - Statistical Data Included

Journal of Sex Research, May, 2000 by Dawn K. Nannini, Lawrence S. Meyers

Evolutionary psychology is the predominant framework within which differences between the sexes in the elicitation of jealousy have been studied. As is true for a number of other behavioral (Buss, 1995a; Tooby & Cosmides, 1992) and psychological (Buss, 1995b; Buss & Kenrick, 1998) differences between men and women, such as expressions of violence, competition, and risk taking, jealousy is said to reflect adaptations to the distinct pressures that men and women faced in their evolutionary past. The era from which many of the proposed adaptations are believed to have derived is the Pleistocene era, a period when homo sapiens are generally assumed to have been organized in hunter-gatherer groups. To the extent that such an organization presented unique demands on the sexes, it is hypothesized that men and women developed somewhat different strategies for their survival.

Consistent with evolutionary theory, proponents of evolutionary psychology have focused their efforts on explaining sexual selection and the extent to which men and women engage in short-term and long-term mating behaviors. Differences in parental investment represent the foundation for the mating strategies to which the sexes have adapted. Because women are more biologically bound to the reproduction of their off spring they are said to be more adapted to long-term mating strategies, while men, the less investing sex, are said to be more adapted to short-term mating behaviors (Buss, 1996; Kenrick, Trost, & Sheets, 1996). That is, men who were less discriminating in choosing a mating partner and more promiscuous were believed to be more successful in passing on their genes than were those who were more discriminating and less promiscuous. For women, on the other hand, sexual selection theory suggests that those who were most concerned with securing a single mate fit to take care of a family were more likely to be reproductively successful.

Evolutionary psychologists have suggested yet another conflict of interest, which together with the sexual conflict in mating strategies resulted in sexual differences in the elicitation of jealousy. This second conflict results from internal fertilization (Trivers, 1972). Upon learning of her impregnation, a woman may be assured that she has been successful in propagating her genetic material. Her male partner's assurance, however, is never so certain, since the moment of fertilization cannot be directly known by him. Men presumably adapted to their situation of paternity uncertainty by exerting sexual control over women's sexuality and developing an inclination toward sexual jealousy (Daly & Wilson, 1998).

Following these evolutionary pressures, evolutionary psychologists have predicted differences in the arousal of men's and women's jealous reactions such that men are believed to be most threatened by their mate's sexual infidelity, and women are believed to be most threatened by emotional infidelity (Buss, Larsen, Westen, & Semmelroth, 1992). With respect to fitness-enhancing strategies, the potential risk to men of females' infidelity is the loss of paternity confidence; thus, a man may unknowingly invest resources in offspring that do not bear his genetic material. Females, on the other hand, certain that their offspring beget their genes, presumably are relatively less concerned with their mate's sexual infidelity; the greater threat for women is the unavailability of their mates' time and resources, a result of emotional infidelity, making it more difficult to raise offspring to the age of sexual maturity.

In an attempt to test this hypothesis Buss et al. (1992) asked men and women to indicate which of two types of infidelity--sexual or emotional--would upset them more. They reported that women more often chose emotional infidelity as more upsetting than did men, while men chose sexual infidelity as more upsetting more often than women. Buss et al. drew similar conclusions using physiological responses as dependent measures; men demonstrated a greater heart rate and electrodermal activity in response to sexual infidelity, and women's electrodermal activity was accelerated in response to emotional infidelity. Harris and Christenfeld (1996) have argued, however, that a closer examination of this gender effect indicates that it has been largely driven by women's strong aversion to emotional infidelity; men have been close to equally split about which of the two types of infidelity would bother them more. While the evolutionary explanation appears to succeed in explaining women's elicitation of jealousy, it falls short in accounting for men's similar reactions to sexual and emotional infidelity (Harris & Christenfeld, 1996).

Wiederman and Allgeier (1993) explained the ambiguous and the sometimes conflicting results of research concerning sexual jealousy to be the result of the interaction between evolutionary dispositions and the influence of culture on shaping the cues and responses involved in situations of infidelity. They recognized that while certain psychological mechanisms, such as a proclivity to react jealously, may have been selected for differently in the sexes due to the unique demands of their evolutionary past, they argued that such mechanisms do not operate outside of a cultural context. Rather, the psychological mechanisms function as cognitive algorithms or frames which structure, and allow for interpretation of, environmental stimuli (Wiederman & Allgeier, 1993). Without denying links to our genetic ancestors, the cognitive algorithms to which Wiederman and Allgeier referred may also be accounted for by social learning theory; in social learning theory they are called schemas, mental frameworks containing information relevant to specific situations or events which, once established, help us interpret situations in the environment (Baron & Byrne, 1997).