SEX DIFFERENCES IN JEALOUSY IN EVOLUTIONARY AND CULTURAL PERSPECTIVE: Tests From the Netherlands, Germany, and the United States

As predicted by models derived from evohttionary psychology. men within the United States have been shown to exhibit greater psychological and physiological distress to sexual than to emotional infidelity of their partner, and wotnen have been shown to exhibit more distress lo emotional than to sexual infidelity. Because cross-cultural tests are critical for evolutionary hypotheses, we examined these sex differences in three parallel studies conducted in the Netherlands fN = 207j, Germany fN = 200), and the United States fN = 224). Two key findings emerged. First, the sex differences in sexual jealousy are robust across these cultures, providing support for the evolutionary psychological model. Second, the magnitude of the sex differences varies somewhat across cultures—large for the United States, medium for Germany and the Netherlands. Discussion focuses an the evolutionary psychology of jealousy and on the sensitivity of sex differences in the sexual sphere to cultural input. Social scientists have frequently' observed that sexual jealousy can be a strikingly strong emotion. In his classic work on the natives of the Trobriand Islands, for example, Malinowski (1932) noted that "jealousy, with or without adequate reason, and adultery are the two factors in tribal life which put most strain on the marriage tie" {p. 97). The sociologist Davis (1948) noted that jealousy is a "fear and rage reaction fitted to protect, maintain, and prolong the intimate association of love" (p. 183). Despite the potentially powerful impact of sexual jealousy, emotion researchers have devoted relatively little attention to it. According to most emotion researchers, jealousy is not a primary emotion. Instead, it is considered a derivative or blend of the more basic, central, primary emotions (Frank, 1988; Hupka, 1984; Plutchik, 1980), As a consequence, it has been relatively ignored by mainstream emotion researchers, who focus their efforts on emotions deemed more basic, such as fear, disgust, and sadness. Recently, however, jealousy has received increasing attention (e.g.. Buss, 1994; Buunk & Hupka, 1987; Salovey, 1991; White & Mullen, 1989). For example, cumulating evidence indicates that male sexual jealousy is a major cause of wife battering and homicide across a large number of cultures (e.g., Daly & Wilson, 1988; Daly, Wilson, & Weghorst, 1982). The two times when a woman faces the greatest risk of harm from a husband or boyfriend are when he suspects her of a sexual infidelity and when the woman decides to terminate the relaAddress correspondetice to David M. Buss, Department of Psychology, University of Texas, Austiti, TX 78712; e-mail: [email protected]. tionship (Daly & Wilson, 1988). Given an emotion powerful enough to provoke violent and sometimes lethal reactions, sexual jealousy can hardly be considered to be a peripheral emotion from the perspectives of the magnitude of arousal, the coherence of events that trigger its activation, and the magnitude of impact on people's lives. Indeed, from these perspectives, a compelling case can be made for the primacy of sexual jealousy as a basic human emotion and for the urgency of understanding its nature and functioning. Although in anthropological records, most acts of violent sexual jealousy are committed by men (Daly et al., 1982), studies in Western cultures fmd few sex differences in sexual jealousy (Salovey, 1991; White & Mullen, 1989). When researchers have asked global questions such as "Do you consider yourself a jealous person?" or "How often do you get jealous?" men and women have typically responded identically (Bringle & Buunk, 1985). Moreover, research has thus farnot convincingly shown that either sex responds more negatively than the other when confronted with the possibility of the partner's sexual involvement with someone else. When differences are found, women usually report more negative feelings than men in response to extradyadic involvement of the partner (Buunk, 1986, 1995; Guerrero, Eloy, Jorgensen, & Andersen, 1993; de Weerth & Kalma, 1993), Until recently, there was not a theory that could predict or explain sex differences in jealousy. Fifteen years ago, however, evolutionary psychologists predicted that, psychologically, the cues that trigger sexual jealousy should be weighted differently in men and women (Daly et al., 1982; Symons, 1979). The evolutionary rationale stems from an asymmetry between the sexes in a fundamental aspect of their reproductive biology; Fertilization occurs internally within the woman. This is not a biological law. There is nothing in evolutionary theory that dictates that fertilization must occur internally within the woman. Although it is a widespread trait, occurring in all 220 species of primates, 4,000 species of mammals, and countless insect species, it is not universal. Fertilization occurs internally within the male in some species (females literally implant their eggs within the male), and it occurs external to both sexes in some species, notably certain fish (Trivers, 1985). The fact that fertilization occurs internally within women, however, means that over human evolutionary history, men have faced a profound adaptive problem that has not been faced by women; uncertainty in their parenthood of children. Some cultures have sayings to describe this phenomenon, such as "mama's baby, papa's maybe." Studies using blood samples or DNA fingerprinting are rare, but estimates based on existing evidence suggest that approximately 9% to 13% of children today have putative fathers that are not their genetic fathers VOL. 7, NO. 6, NOVEMBER 1996 Copyright © 1996 Atnerican Psychological Society 359 PSYCHOLOGICAL SCIENCE Sex Differetices in Jealousy (Baker & Beilis, 1995). Paternity uncertainty, in short, is not just a hypothetical possibility. It is a reality and probably has been throughout human evolutionary history. From a man's perspective, in the evolutionary past, a sexual infidelity on the part of his mate would have been tremendously damaging in reproductive currencies because of compromises in paternity certainty. First, the man would risk losing the mating effort he expended, including time, energy, risk, and nuptial gifts devoted to attracting and courting the woman. Second, he would suffer mating opportunity costs lost through foregone chances to attract and court other women. Third, the man would risk losing the woman's parental effort because it might be channeled to a competitor's child and not his own. Fourth, and perhaps most important, if the man would invest in the child, he would risk investing resources in a genetic vehicle that did not contain his genes. Because of the large costs linked with compromises in paternity, evolutionary psychologists have predicted that men's sexual jealousy will be triggered centrally by cues to sexual infidelity. Women have faced a different set of adaptive challenges. A mate's sexual infidelity does not jeopardize a woman's certainty in parenthood. The child is her own regardless of her mate's sexual philandering. Nonetheless, if her mate becomes interested in another women, she risks losing his time, energy, resources, parental investment, protection, and commitment— all of which could get diverted to a rival woman and her children. Because the emotional involvement of a man with another woman is a reliable leading indicator of the potential diversion and loss of the man's investment, evolutionary researchers have proposed that cues to emotional infidelity would be central triggers of women's jealousy (Buss, Larsen, Westen, & Semmelroth, 1992). The predicted sex differences have been found within the United States. In a series of forced-choice experiments, men indicated greater distress to a partner's sexual than emotional infidelity, whereas women indicated greater distress to a partner's emofional than sexual infidelity (Buss et al., 1992). These findings have been replicated by other researchers within the United States (Wiederman & Allgeier, 1993), and show up in measures of physiological distress as refiected by increased electromyographic activity, increased electrodermal response, and elevated heart rate (Buss et al., 1992). In addition, some earlier studies offered findings in line with the evolutionary perspective. Francis (1977), for example, found that among men, sexual involvement with a third person was the most mentioned situation evoking jealousy, whereas among women, the partner spending time or talking with a third person turned out to be the most frequently mentioned triggers of jealousy. Cross-cultural data, however, are crucial for testing this evolution-based hypothesis. First, because the sex-hnked triggers are hypothesized to be species-typical characteristics of evolved human psychology, data from other cultures are required for adequate testing (see, e.g., Symons, 1979). Second, it is weli documented that cultures differ tremendously in their attitudes toward aspects of sexuality such as premarital sex and extramarital affairs (see, e.g.. Buss, 1989; Frayser, 1985). For example, whereas over 75% of the U.S. population unequivocally disapproves of extramarital sex, the comparable percentage in the Netherlands is less than 45% (Buunk & van Driel, 1989). Furthermore, cultures differ in their emphasis on sexual equality (Frayser, 1985). Cultures that emphasize sexual equality and have particularly liberal attitudes about sexuality for both women and men should provide an especially rigorous challenge for testing the hypothesized sex differences in sexual jealousy. Thus, we sought to conduct parallel studies in three countries with different cultures—the Netherlands, Germany, and the United States. In particular, including the Netherlands seems appropriate because the Dutch appear to downplay sex differences and emphasize equality between the sexes more than people from virtually any other culture for which reliable data exist (Hofstede, 1994). STUDY 1; THE UNITED STATES