Exploring An Evolutionary Theory Of Jealousy Through Sexual And Emotional Infidelity
Evolutionary theories of jealousy, popularised in psychological circles by the research of Buss, Buunk and their colleagues, have aroused criticism by other researchers claiming that the design of these studies was confounded by a number of factors. This study in particular will test the ‘double-shot’ hypothesis of De Steno & Salovey in order to ascertain whether a 1992 study by Buss et al. still holds true when more rigorously tested on a larger population. Three questions regarding the activation of jealously via sexual and emotional infidelities will be considered in order to perform this test, then compared to the findings of previous studies in this field.
Jealousy; deadly sin, or evolved trait for genetic survival? Many recent studies in evolutionary psychology have probed this particular emotion in an attempt to identify a difference between the sexes. Buss et al (1992) of the University of Michigan conducted a study to define the activation of jealousy in male and female participants. This prompted later researchers to perform studies that questioned both the suitability of the apparatus used by Buss et al (1992), and the value of the data obtained for supporting their theoretical base. One of the limitations identified by De Steno & Salovey (1996) was what they termed a “double-shot” hypothesis; a tendency to equate emotional infidelity with sexual infidelity may have arisen from the wording of the questions. However, some of these later studies have been limited by the size of their populations, an issue we plan to investigate here.
It is important to identify differences that may exist between the sexes in order to establish a body of evidence that is testable against current and future theories of the evolutionary development of emotion. If jealousy is a genetic survival trait then, in theory, we should see a difference between males and females in activation of distress at emotional and sexual infidelity; males, having less certainty as to their paternity of a foetus, should report sexual infidelity as more distressing.
There are three questions that this study hopes to address. It is hypothesised that in the current study there will be no significant difference between the sexes in the activation of sexual jealousy by emotional infidelity; both sexes will interpret emotional infidelity in a similar fashion. However, it is further hypothesised that male respondents will continue to report greater distress at sexual, compared to emotional, infidelity even when the ‘double-shot’ issue is addressed. Finally, this study hopes also to show that the results obtained by Buss et al (1992) showing a discrepancies between the sexes in the amount of distress caused by each type of infidelity can be reproduced using a continuous question format if the population is large enough. It is hypothesised that males will report greater distress at sexual infidelity than emotional, with the converse true for females. It is my belief that an evolutionary theory of jealousy will be supported for the most part, with studies such as that performed by De Steno & Salovey (1996) found to be extremely useful in refining our understanding of this topic.
The population of the current study was drawn from volunteer first-year psychology students, and their friends and families. A total of 413 participants responded to the anonymous online survey; 103 Male (24.94%) and 310 Female (75.06%). The mean age of the sample was 22.95 years with a standard deviation of 8.46.
The survey administered to participants was formulated using the item formats of preceding studies (Buss et al., 1992; De Steno & Salovey, 1996) and administered in an anonymous online environment. The survey consisted of a small number of qualitative questions on the genetic and cultural origins of the participant, the bulk of the remaining answers being in the form of forced choice and grading on a likert scale. The survey as administered to participants is presented in the appendices.
Students enrolled in “Introduction to Psychology B” at Deakin University were requested to complete a survey, anonymously and voluntarily, regarding the elicitation of jealousy via sexual and emotional infidelity. To encourage a greater response participants were informed that they may request their friends or family to complete the survey as well.
In an attempt to alleviate any order induced distortion of the emotional/sexual infidelity questions, scenarios A and B were inverted for certain participants; these participants were selected based on their birthday falling on an even or odd date.
Data collected from the online questionnaire was then analysed by the psychology staff of Deakin University and presented to students for preparation of the laboratory reports.
In order to test our first hypothesis, an independent samples t-test was performed on responses recorded by males’ and females’ to Question 26 on the survey: “How likely do you think that it could be that your partner could form a deep emotional attachment with another person without also being sexually attracted to that person?” Participants answered the question by rating it on likert scale ranging from 1 (extremely unlikely) to 7 (extremely likely). Mean ratings made by each sex are provided for consideration in Table 1.
While the data presented in Table 1 is suggestive of the hypothesised effect, with males scoring higher that females on the item, the difference was not significant t(228)=0.44, p>0.05. As such, females and males did not differ in the likelihood that they would report that their partners could become emotionally involved with another person without also becoming sexually attracted to that person.
In response to the forced-choice formatted question with the ‘double-shot’ removed, 66% of males reported more distress regarding sexual infidelity, while 50% of females reported more distress at the possibility of a partner’s emotional infidelity. Application of χ2 analysis indicated that this pattern represented a significant relationship between sex and responding χ2 (df = 1, 410) = 7.36, p<0.05. This supports the hypothesis that males will report a greater disparity in the distress caused emotional and sexual infidelity than females. Data obtained for the purposes of addressing research question 3 is presented in Figure 1. Examination of Figure 1 indicates that for males emotional infidelity in a partner was rated as less distressing than sexual infidelity. Statistical analysis via paired samples t-test indicated that this difference was significant t(94)=4.29, p<0.05. For females, emotional infidelity in a partner was rated as less distressing than sexual infidelity. Statistical analysis via paired samples t-test indicated that this difference was significant t(294)=5.27, p<0.05. Further examination of the results displayed in Figure 1 indicates that, overall, compared with men, women rate infidelity as more distressing, regardless of whether it is emotional or sexual. Discussion The questions that we set out to test responded well to the study, and the results refute to a large extent the confounding effects attributed to the ‘double-shot’ limitation. The hypothesis that there would be no significant difference between the sexes regarding the activation of sexual jealousy by emotional infidelity was supported by our study; the hypothesis that male respondents would continue to report greater distress at sexual, compared to emotional, infidelity even when the ‘double-shot’ issue was addressed was also supported. Finally, the hypothesis that males would report greater distress at sexual infidelity than emotional, with the converse true for females was partially supported. The hypothesis held true for males, however females were shown to be the same as males in this respect. A logical inference that could be made based on the literature available at the time of this study (Buss et al., 1992; Buunk et al., 1996) is that females would be more likely to equate emotional infidelity with sexual infidelity than males. Studies such as the one performed by De Steno & Salovey (1996) have concluded that this effect may have been due to the wording of the questionnaire, thus invalidating most of the evidence cited by Buss et al (1992). The independent t-test of the results garnered from question 26 suggests that this is not the case; males and females are almost equally as likely to assume sexual infidelities will arise from emotional infidelity. An interesting point to highlight is that females reported greater distress overall when faced with infidelity. This is a possible explanation for the conclusion De Steno & Salovey (1996) recorded when studying a smaller population to test their ‘double-shot’ argument. When further addressing the ‘double-shot’ issue it was ensured that scenarios designed to test this were clearly worded to include one type of infidelity while emphatically ruling out the other. Again of note is the level of distress reported by each gender as presented in Figure 1. Both sexes reported sexual infidelity as a more distressing scenario, however the level of distress female participants reported regarding emotional infidelities was closest to the distress reported by males regarding sexual infidelities. This supports the premise that the ‘double-shot’ may have been conceived to explain away a confusion in thinking; inadvertently contrasting the distress of males at sexual infidelity with that of females at emotional infidelity in the minds of the designers of previous studies. The final question addressed by our current study was to ascertain whether or not the results of Buss et al. (1992) could be reproduced using a continuous choice methodology. By utilising a much larger population we had an opportunity to confirm that males indeed report greater distress over sexual infidelities than emotional ones. In this respect our hypothesis was supported. The females in our sample population, however, reported the same trend of preferring emotional infidelity to sexual; our hypothesis that females will find emotional infidelity more distressing has therefore not been supported. This is important in light of the theory proposed by evolutionary psychologists that females should regard emotional infidelity as more distressing based on the certainty of their maternity, and the need for protection and support throughout the pregnancy and early life of the child. The different needs of males and females throughout the reproductive cycle was supposed to have been supported by the existence of two activation routes for jealousy, the more “suitable” of which being more sensitive. As this does not seem to be true based on the results of this study, further questions must be asked as to the suitability of an evolutionary theory of jealousy. Limitations There are a number of limitations to the current study. The impact of culture on the activation of jealousy (Buunk & Hupka, 1987, Buunk et al, 1996) should be considered, and thanks to the inclusion of questions assessing the cultural demography of our participants it may be possible to incorporate this information in a meaningful way. The penultimate likert item aggregated into the “distress score”, Interested, is not necessarily an indicator of distress. If the remaining indicators show a pattern of “non” distress with only the Interested indicator rated highly, a slight emphasis towards distress will manifest where it possibly should not have. While this is not a factor that has had a confounding effect on the present study in the future it may be advisable to modify the scale, especially if testing populations that may respond inaccurately to a questionnaire couched in western culture. The conditioning effects of past and current relationships should also be taken into account when considering the data. For example, it could be that their life experience has taught them that it’s “better” to let their partner cheat than to make an issue. The level of jealousy reported by these participants could be significantly lower than what they actually experience when it happens. A limited sample of homosexually oriented participants prevents drawing inferences regarding jealousy in same-sex attracted individuals; partners with an inability to share the genetic familiaris of their young. This would be an interesting question to address, as gender may play as large a role in the evolution of jealousy as sex appears to. Considering that the current study has already debunked the commonly held belief that females will become more distressed at emotional rather than sexual infidelity it would be interesting to see if other, more damaging, stereotypes could be dispelled. (Abstract: 107 words) (Body: 1,895 words) References Buss, D.M., Larsen, R.J., Westen, D., & Semmelroth, J. 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