Sex differences in jealousy: the processing of cues to infidelity

Abstract

The hypothesis derived from the evolutionary view of jealousy that men's jealousy mechanism (JM) preferentially processes cues signaling a mate's sexual infidelity, whereas women's JM preferentially processes cues signaling a mate's emotional infidelity was tested. Depending on the condition, the participants were successively presented with a series of cues signaling either a mate's sexual or emotional infidelity in ascending order of cue diagnosticity. The participants had to determine two thresholds of the jealousy feeling. The first threshold dealt with the cue to infidelity that elicits a first pang of jealousy. The second threshold concerned that cue to infidelity where the intensity of the jealousy feeling becomes intolerable. No sex-specific differences were found with respect to the number of cues to sexual or emotional infidelity until the first threshold. However, after the first feeling of jealousy had been elicited, men needed significantly fewer cues to sexual infidelity and women needed significantly fewer cues to emotional infidelity until the second threshold. Moreover, men were significantly faster in determining the two thresholds for cues to sexual infidelity, whereas women were significantly faster for cues to emotional infidelity. The implications of the present findings are discussed.

Introduction

Evolutionary psychologists view jealousy as a psychological mechanism that recurrently solved an essential problem of individual reproduction in our evolutionary history: infidelity in reproductive relationships (Buss et al., 1992, Cosmides & Tooby, 1994, Daly et al., 1982, Symons, 1979). A distinctive feature of the evolutionary view is the assumption of a sex-specific jealousy mechanism (JM) because men's and women's reproductive success has been recurrently threatened by different types of infidelity. Specifically, a woman's sexual infidelity deprives her mate of a reproductive opportunity and may burden him with years of investment in a genetically unrelated child. In contrast, a man's infidelity does not burden his mate with unrelated children, but it may divert resources away from his mate's progeny. This resource threat may be signaled by his level of emotional attachment to the other female. As a consequence, men's JM is hypothesized to be particularly activated by a mate's sexual infidelity, whereas women's JM is hypothesized to be particularly activated by a mate's emotional infidelity.

The evolutionary view of a sex-specific JM spawned an impressive body of research during the past decade that has been primarily devoted to testing the hypothesis that the female JM responds with stronger emotions to a mate's emotional infidelity, whereas the male JM generates stronger emotions in response to a mate's sexual infidelity (see Harris, 2003, for a critical review; and Hofhansl, Vitouch, & Voracek, 2004, for a more recent and complete meta-analysis that supports the evolutionary view).

The present research focuses on the hypothesis derived from the evolutionary view of jealousy that the JM is a sex- and content-specific information-processing device (Schützwohl & Koch, 2004). More precisely, the male JM is hypothesized to preferentially process cues signaling a mate's sexual infidelity, whereas women's JM is predicted to preferentially process cues signaling a mate's emotional infidelity. This hypothesis has received empirical support in two recent studies. Schützwohl and Koch (2004) showed that men were better able to recall cues signaling their mates' sexual infidelity, whereas women were better able to recall cues signaling their mates' emotional infidelity. Additionally, Schützwohl (2004a) found that decisions in a forced-choice response format in favor of the evolutionary primary infidelity type (i.e., female sexual and male emotional infidelity) were made significantly faster than decisions in favor of the adaptively secondary infidelity type (i.e., female emotional and male sexual infidelity). The present study extends this line of research with respect to two aspects of the preferential processing of cues to the adaptively primary infidelity type. First, the present study examines the number of cues to sexual or emotional infidelity that men and women need to process until the first sign of feeling jealous is elicited and until the jealousy feeling becomes intolerable. Second, it investigates the efficiency of the processing of the cues indicating these two jealousy thresholds.

More specifically, depending on the condition, men and women were successively presented with cues signaling either a mate's sexual or emotional infidelity. These cues were ranked from the lowest to the highest diagnostic cue for the respective infidelity type. The participants were asked to indicate two different thresholds with respect to their jealousy feelings elicited by these cues. The first threshold concerned that cue to infidelity where they felt the first pangs of jealousy. The second threshold concerned that cue to infidelity where the intensity of the feeling of jealousy became intolerable. It was hypothesized that men would require fewer sexual infidelity cues than women would to reach the two thresholds. Conversely, women were predicted to require fewer emotional infidelity cues than men would to reach the thresholds. Additionally, as an index of processing efficiency, the decision times for the determination of the two thresholds were registered. It was hypothesized that men would more efficiently process sexual infidelity cues (i.e., need less time), whereas, conversely, women would more efficiently process emotional infidelity cues.