THURSDAY, Jan. 23 (HealthDay News) -- The results of a new speed-dating study suggest that when romantic sparks fly, so do testosterone levels, with mutual attraction giving rise to a hormonal spike in both men and women.
"The findings do suggest that we have some sort of 'radar' to detect who's attracted to us ... but it's not clear from this study whether people are consciously aware of this or not," said one outside expert, Dr. Robin Edelstein, an assistant professor of psychology at the University of Michigan, Ann Arbor.
In the new study, roughly 200 heterosexual men and women volunteered to take part in about 2,000 speed-dates.
All participants offered up four saliva samples for hormone analysis. Two were taken a week before their speed-dates, while another two swabs were obtained right before and after the dates.
The result: Testosterone levels did not rise as a result of one-sided attraction. When the feeling was mutual, however, both men and women experienced a testosterone bump, the researchers found.
In other words, unless the feeling was mutual, simply being liked by a date ("romantic popularity") or liking a date ("romantic attraction") was not enough to affect hormone levels in either gender.
"Many people think that only men have testosterone, but that's not the case," explained study lead author Eli Finkel, a professor of social psychology at Northwestern University in Evanston, Ill. "It's true that men have much more testosterone than women do, but the links between testosterone and social outcomes are similar for men and women, and testosterone is associated with a stronger sex drive in both sexes."
"For 50 years, researchers have shown that male animals -- rabbits, monkeys, starlings -- exhibit a spike in testosterone and engage in mating-initiation behaviors when introduced to a female they hadn't met previously," Finkel said. But he added that the spike typically occurs only when the animals "have a realistic chance of mating."
"Now consider humans," Finkel said. "It is extremely rare that humans mate in the absence of mutual consent. Feeling attracted to a new person, or having that person be attracted to you, is not a reliable indicator that you have a good chance of initiating a sexual relationship with him or her. Mutual attraction is required for that."
So, a spike in testosterone may "promote efforts toward establishing a relationship with the other person," Finkel theorized.
He and his colleagues presented their findings this month at the annual meeting of the Society for Personality and Social Psychology in New Orleans. Data and conclusions presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.
According to Edelstein, the Northwestern research opens up "really interesting questions."
"The [hormonal] changes are specific to mutual attraction, suggesting some sort of effect of 'chemistry,'" she noted. So, "how accurate are people about this mutual attraction, and are some people better at detecting it than others? And might those differences be related to testosterone?"
Another expert said the study had real merit.
The study "confirms past research that has shown that the feeling that someone else is attracted to us is one of the strongest contributors to us being attracted to them in return," said Jeffrey Hall, an assistant professor in the department of communications studies at the University of Kansas, in Lawrence.
"If you actually ask people to list what they most want in another person, right up toward the top is finding someone who is attracted to them," he noted. "It's such a strong effect that just the thought that another person might be attracted to us is compelling. So in being able to show physiological evidence of mutual interest, I think this study is very exciting."
For more about testosterone, visit the U.S. National Library of Medicine.
SOURCES: Eli Finkel, Ph.D., professor, social psychology, Northwestern University, Evanston, Ill.; Jeffrey Hall, Ph.D., assistant professor, department of communications studies, University of Kansas, Lawrence, Kan.; Robin S. Edelstein, assistant professor, department of psychology, University of Michigan, Ann Arbor; Jan. 18, 2013, presentation, Society for Personality and Social Psychology annual meeting, New Orleans
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