Recent scientific studies have shown that the flame of jealousy burns most fiercely in men at thoughts of a partner's sexual infidelity while women get most green-eyed at the idea of emotional infidelity. Researchers are still investigating the root causes of this jealousy gender gap, with some maintaining that it's due to hard- wired genetic responses honed by millennia of evolution and others contending it's cultural at heart.
Proponents of a genetic cause for jealousy argue that male ancestors who could assure a mate's sexual fidelity were more likely to sire offspring, while women who lost the support of a mate were less likely to successfully raise children to maturity. Through natural selection, therefore, men who reacted to signs of infidelity with jealousy eventually dominated the population, as did women who struggled against losing a mate's emotional commitment.
Yale psychologist Peter Salovey, whose own studies ascribe the differences primarily to cultural causes, was one of the researchers who debated the nature-nuture question in the November issue of the journal Psychological Science. "Before we start looking for the 'jealousy gene' and attributing spousal abuse to inescapable biological urges, let's reflect on the kinds of data that have actually been collected," cautioned Mr. Salovey, who is professor of psychology and of epidemiology and public health.
In studies by investigators on both sides of the nature-nuture debate, subjects are asked to choose the more distressing alternative: sexual or emotional infidelity. Professor Salovey and former Yale graduate student David A. DeSteno -- now a psychologist at Ohio State University -- delved more deeply into this issue in two studies they conducted. They asked the subjects to gauge how firmly they believed the two types of infidelity are linked.
"Women in our studies were more likely than men to expect that emotional infidelity by their partners implied associated sexual infidelity. For them, emotional infidelity really represented two types of infidelity as opposed to one," explained Professor Salovey. "This is what David DeSteno and I call the 'double-shot' hypothesis. The occurrence of both types of infidelity is more troubling than either type individually and signals a greater threat to the relationship."
The first study involved 114 undergraduate students -- 53 male and 61 female -- with a mean age of 19.8 years. In the second study, the Yale researchers sampled 135 nonstudent adults -- 73 male and 68 female -- ranging in age from 17 to 70, who were enrolled in health-related continuing education classes in several Midwestern cities. In both groups, men tended to view sexual and emotional infidelity as being weakly linked, while women believed that sexual infidelity could occur without emotional infidelity, but not the reverse. Researchers elsewhere have also founded evidence for this "double-shot" perspective on infidelity among women.
"Jealousy, we believe, is a multifaceted phenomenon in which evolution plays a role," noted Professor Salovey. "We agree that jealousy may possess some benefits for natural selection, just as evolutionary psychologists share our view that socialization helps shape jealousy. But we argue that socialization can explain most of the gender differences found in responses to these kinds of questionnaires.
"Obviously, we believe in evolution. We just don't buy that these kinds of data represent a very stringent test of evolutionary explanations for sex differences in jealousy," he said.