The adultery website AshleyMadison.com isn't good just for two-timing — it can drive scientific research.
To study infidelity, researchers scanned publicly accessible ads from 200 men and 200 women chosen at random from the site, which was started in 2001 and, as a "discreet dating service," caters primarily to people already involved in a relationship. (The name of the site was taken from two popular names for baby girls back then, supposedly in an effort to attract women.)
"The study of adultery is important in the broad sense, because it helps us understand who we are," researcher James Hare, a behavioral ecologist at the University of Manitoba in Canada, told LiveScience.
"Humans are inclined to put themselves on a pedestal above other living things, though time and time again, data reveal that we are a product of the same selective forces and evolutionary processes that have shaped all life.
"To me, acceptance of this fact diminishes the sense of entitlement humans feel and, in the end, fosters an ethic that is more in accord with the world around us — and ultimately less likely to lead to the demise of our species and those we share the planet with."
The researchers investigated what the would-be cheaters said they wanted in an adulterous relationship: "anything goes," "short term," "undecided," "long term," "cyber affair/erotic chat," or "whatever excites me." They also noted the ages of the advertisers, the ages of the partners they sought, and the total number of adjectives they used in describing themselves and in what they wanted in a partner — specifically, adjectives involving wealth, physical attributes, educational achievement and athletic prowess. (Naturally, the investigators were not given the names or other personal details of the customers they studied.)
Their findings conformed to common stereotypes of men as promiscuous and women as choosy. The men, who averaged about 42 years old, advertised "anything goes" more than twice as often as women, while the women, who averaged about 39, sought long-term relationships about two-thirds more than men.
In addition, women used more adjectives to describe the wealth and physical attributes they wanted in partners, while men used more adjectives when it came to describing their own wealth, athletic interests and educational achievements.
The findings suggest preferences in partners even among married people are based on female attempts to get at male-controlled resources, the researchers said.
Women who were in relationships used significantly more adjectives describing the physical attributes they sought in partners and significantly fewer ones describing their material qualities than single women did. This suggests women in relationships are driven more by urges for good genes for potential progeny than for material benefits, Hare said. Although the women in this study were near or past the end of child-bearing age, "many of the women would still be capable of reproduction," he added. Even for those who were not, there is still "the satisfaction derived from mating with a physically fit partner," Hare said.
The scientists detailed their findings online Oct. 17 in the journal Evolutionary Psychology.
Related on LiveScience.com: