Abstract
The present studies address two criticisms of the theory of evolved sex differences in jealousy: (a) that the sex difference in jealousy emerges only in response to hypothetical infidelity scenarios, and (b) that the sex difference emerges only using forced-choice measures. In two separate studies, one a paper-and-pencil survey with a student sample and the other a web-based survey targeting a non-student sample, men and women showed significant sex differences in jealousy in response to
Introduction
According to the theory of evolved sex differences in jealousy (Buss, Larsen, Westen, and Semmelroth, 1992; Daly, Wilson, and Weghorst, 1982; Symons, 1979), ancestral women's challenge of ensuring paternal investment exerted selective pressures that increased women's jealousy in response to emotional infidelity, whereas ancestral men's challenge of paternal uncertainty exerted selective pressures that increased men's jealousy in response to sexual infidelity. The majority of studies testing this theory have examined men and women's responses to hypothetical infidelity scenarios in which participants must choose which type of infidelity (sexual or emotional) is more distressing or upsetting. Although studies using this forced-choice methodology generally find that a higher proportion of men than women choose the sexual infidelity as more distressing (Harris, 2003), reliance on this methodology has led to a number of serious challenges, including: (a) that sex differences in jealousy are not replicable with continuous measures of jealousy, and (b) that sex differences in jealousy do not emerge when people report their reactions to actual infidelity experiences.
Sex Differences in Jealousy using Continuous Measures
The majority of studies examining sex differences in jealousy have used the forced-choice methodology (Buss et al., 1992; Harris, 2003). This methodology was favored because both men and women were expected to have strong jealous reactions to sexual and emotional infidelity due to their co-occurrence throughout history, and the forced-choice method allows for a cleaner separation of reactions to both types of infidelity. However, a number of critics have argued that sex differences in jealousy are not replicable with continuous measures of jealousy (DeSteno, Bartlett, Braverman, and Salovey, 2002; DeSteno and Salovey, 1996; Harris, 2003). Although Sagarin (2005) noted that some studies have found significant sex differences using continuous measures (Sagarin, Becker, Guadagno, Nicastle, and Millevoi, 2003; Sheets and Wolfe, 2001; Wiederman and Allgeier, 1993; See also Pietrzak, Laird, Stevens, and Thompson, 2002), Harris (2005) responded that other studies, including one with a large random sample (Green and Sabini, 2004), failed to find significant sex differences.
The failure to find sex differences in a large random sample (Green and Sabini, 2004) is particularly troubling for the theory of evolved sex differences in jealousy. But an examination of Green and Sabini's data (with permission of the first author; Green, personal communication, March 11, 2005) suggests that the lack of a significant sex difference might have stemmed from a ceiling effect in the data. Participants were asked to imagine that their romantic partner has become interested in someone else. They were then asked how distressed or upset they would be when imagining an emotional infidelity. On a seven-point scale with 1 labeled
Because a partner's infidelity will typically elicit an intense jealous reaction, the use of “very” as an upper anchor label may have effectively condensed the usable portion of the scale. Indeed, in Green and Sabini's (2004) sample, over 95% of participants responded using the top four points on their seven point scale (the majority using the uppermost point). To remedy this, the present studies used a jealousy scale adapted from Harris (2002) with a lower anchor labeled
Sex Differences in Jealousy in Response to Actual Infidelity
Harris (2002) argued that responses to hypothetical infidelity scenarios might not align with responses to actual infidelity experiences. As evidence, Harris replicated the sex differences using the traditional forced-choice hypothetical questions, but when participants were asked about their reactions to actual infidelity, both men and women reported that they focused on the emotional aspects of the infidelity more than the sexual aspects. However, as discussed in Sagarin (2005), Harris' change from hypothetical infidelity scenarios to actual infidelity experiences was confounded with a change in the construct being measured (participants reported their
Berman and Frazier (2005) partially explored this issue using a forced choice item that asked past victims of infidelity whether they were more distressed or upset by their “partner's emotional attachment to the other person” or their “partner's enjoying sexual activities with that other person” (p. 1621). They replicated the sex differences using the traditional forced-choice hypothetical questions, but when the questions were asked about actual infidelity they found no difference between the sexes. However, Berman and Frazier (2005) used a different method of identifying past victims of infidelity that yielded a much smaller proportion of participants identified as experiencing infidelity. Specifically, whereas Harris (2002) found that 65.3% of heterosexual women and 58.3% of heterosexual men in her sample said yes to the question “Have you had any experiences in which someone you were romantically involved with ‘cheated on’ you?” (p. 9), Berman and Frazier (2005) found that 16.7% of women and 13.1% of men in their sample indicated that “a romantic partner had been unfaithful to them sometime in the past year” (p. 1620) according to a specific definition of infidelity (“a romantic, sexual, or emotional relationship with someone other than the primary partner that was kept secret from that partner and that would have been unacceptable to the partner if s/he had known,” p. 1620). This led to an
The present studies used Harris's (2002) method of identifying past victims of infidelity and found proportions of past victims similar to Harris (2002).
Current Studies
In two studies, we examined whether a sex difference in jealousy emerges in response to actual experience with infidelity using both continuous and forced-choice measures. In Study One, we administered a paper survey to undergraduate students. In Study Two, students recruited working adults to participate in a web-based survey.
Study One
Methods
Participants
Two hundred fifteen students participated in this experiment (53 men, 162 women,
Procedure
Students completed a three-page survey in class for extra credit. The first page contained demographics and asked whether the participant had ever been cheated on. If the participant had been cheated on they proceeded to the second page, otherwise the participant skipped to the third page. The second page asked how emotionally distressed the participant was by the infidelity, how jealous they were in response to the emotional and sexual aspects of the infidelity (answered on seven-point scales with end points labeled “not at all” and “completely”), a forced-choice jealousy item (“Which aspect of the infidelity made you more jealous?” with options “Sexual” and “Emotional”), how much the participant focused on the emotional and sexual aspects (answered on seven-point scales with end points labeled “not at all” and “completely”), and a forced-choice focus item (“Which aspect of the infidelity did you focus on?” with options “Sexual” and “Emotional”). The third page contained Buss et al.'s (1992) hypothetical infidelity scenario.
Results and Discussion
When recalling actual experiences with infidelity, men reported greater jealousy in response to the sexual aspects (
The sex difference was attenuated in response to the focus items derived from Harris (2002). Men focused more on the sexual aspects (
When thinking about a hypothetical infidelity, men reported greater jealousy in response to the sexual aspects (
Study Two was designed to replicate these findings using a different method of data collection and a non-student sample.
Study Two
Methods
Participants
One hundred and thirty six people participated in this experiment (40 men, 96 women,
Procedure
Psychology undergraduates recruited working adults to participate in a web-based survey (adapted from Study One). Recruiters were given the web address of the survey and were offered extra credit points for recruiting up to three people to participate in the study. The web survey included a field for participants to report the person who should receive credit for their participation. To ensure anonymity of responses, this name was submitted to the researchers separately from the rest of the survey responses. Jealousy and focus questions, as well as emotion and sex questions were counterbalanced. Continuous measures always preceded forced-choice measures. This was done to ensure that participants would not use their responses from the forced choice measure in deciding how to respond to the continuous items.
Results and Discussion
Consistent with Study One, when recalling actual experiences with infidelity, men reported greater jealousy in response to the sexual aspects (
Because one of the primary goals of Study Two was to examine sex differences in jealousy in response to actual infidelity in a non-student sample, we ran an additional set of analyses using only the working adult portion of the sample. The same pattern of results emerged. When recalling actual experiences with infidelity, men reported greater jealousy in response to the sexual aspects (
Also consistent with Study One, men focused more on the sexual aspects (
For participants who had not been cheated on, men reported greater jealousy in response to the sexual aspects (
Discussion
The present research addresses two criticisms raised by Harris (2002; 2003; 2005): (a) that the sex difference in jealousy emerges only in response to hypothetical infidelity scenarios, and (b) that the sex difference in jealousy emerges only using forced-choice measures. In two separate studies, one a paper-and-pencil survey with a student sample and the other a web-based survey targeting a non-student sample, men and women showed significant sex differences in jealousy in response to actual infidelity experiences. Furthermore, these sex differences emerged using both continuous measures of jealousy as well as the traditional forced-choice measure. Moreover, these studies showed that the sex differences are not attenuated in an adult sample.
The present results also withstand an additional concern raised by Harris (2005). Specifically, Harris (2005) argued that interactions on ordinal scales are interpretable only if they include a sign change or a cross-over pattern. In Study One, the critical interaction showed a sign change with men reporting greater jealousy in response to the sexual aspects of the infidelity than the emotional aspects and women reporting greater jealousy in response to the emotional aspects of the infidelity than the sexual aspects. In Study Two, this sign change occurred within the context of a cross-over interaction. Thus the interactions in both studies are interpretable despite the use of ordinal jealousy scales.
Smaller, often marginal or non-significant sex differences emerged for the focus items. These results help to resolve the otherwise contradictory findings of Harris (2002), suggesting that the lack of a sex difference found when Harris (2002) asked participants how much they focused on each aspect of the infidelity stemmed from Harris's use of the term “focus” instead of “jealousy.”
The present studies did not assess whether the infidelities experienced by participants were purely sexual, purely emotional, or both sexual and emotional. However, for three reasons, it seems unlikely that systematic differences in the type of infidelity experienced by men and women could account for the observed sex differences in jealousy. First, Berman and Frazier (2005) investigated this issue and did not find a sex difference in the types of infidelity experienced by men and women. Second, in our studies, very few participants (6%) indicated that the sexual or emotional aspects of the infidelity caused no jealousy, suggesting that the infidelities experienced by our participants included both sexual and emotional components (see Buss, 2000, for a discussion of the co-occurrence of sexual and emotional infidelity). Third, given men's greater predisposition than women toward short-term sexual liaisons (Buss and Schmitt, 1993), women would probably be more likely than men to have been the victims of purely sexual infidelities. Nevertheless, women reported greater jealousy in response to the emotional aspects of the infidelities than the sexual aspects.
A large number of studies have examined sex differences in jealousy using hypothetical infidelity scenarios, and a growing number have used retrospective reports of actual infidelity. Future research could profitably expand beyond these traditional methods of research in this domain. One promising option would be to create jealousy-provoking situations in a laboratory and examine the jealous reactions. Jealousy could be provoked in existing couples through the flirtatious advances of a confederate, or non-coupled participants could be bonded through guided self-disclosure (Melinat, 1991) and then the bond could be threatened by a rival. Of course, these methodologies raise numerous ethical and practical challenges, most importantly ensuring the welfare of the participants and their relationships. But if these challenges could be overcome, such methodologies could provide a valuable opportunity to examine real jealousy as it occurs.
In conclusion, our results demonstrate than sex differences in jealousy are not limited to responses to hypothetical infidelity scenarios. Sex differences also emerge in response to actual infidelity experiences.
Footnotes
One participant failed to complete the focus forced choice item, and two participants failed to complete the jealous forced-choice item, and they are not included in the respective analyses.
Some authors (Harris, 2005) have argued that main effects are relevant in examining sex differences in jealousy, whereas other authors (Sagarin, 2005) have argued that the interaction is the only relevant effect. As this is a continuing debate in the literature, we have presented the full analyses to allow readers to make their own determinations.
In Study One, all participants (regardless of their infidelity experience) responded to the hypothetical infidelity scenario. As a result, the analysis of responses to the hypothetical infidelity scenario includes more participants than the analysis of responses to the actual infidelity experiences. In Study Two, only participants who had never been cheated on responded to the hypothetical infidelity scenario.
Footnotes
Acknowledgements
Some of these findings were initially presented at the 2005 Midwestern Psychological Association's Annual conference. We thank anonymous reviewers for their helpful comments on earlier drafts of this paper. Finally, we wish to thank our research assistants, Nikki Accurso, Sharon Braunling, and John Healy.