On March 10, a new study published in the Proceedings of The Royal Society B: Biological Sciences, scientific journal devoted to biology, found men alter their mating choices based on stress levels.

Researchers at the University of Trier in Germany and Wake-Forest University in the US studied the stressed and relaxed states of a group of heterosexual males to determine if the subjects would change the common preference of "self-resembling mates." The findings revealed, "stress affects human mating preferences: unstressed individuals showed the expected preference for similar mates, but stressed individuals seem to prefer dissimilar mates."

Co-author of the study, Christian Deuter, a psychobiologist at the University of Trier, told Relaxnews, "stress is known to have severe effects on many aspects of our behavior, mostly negative. Still, the fact that it also has an impact on our mating preferences in such a fundamental way was very astonishing. It would also be interesting if female mating behavior is affected in a similar way." 

The study was conducted by showing the subjects a series of images while at relaxed and stressed states measured by biometric responses after placing their hands in pleasant and unbearable temperatures of water. The images were classified as neutral, erotic female nudes and modified erotic females nudes that were facially altered with their features or the features of other participants. In the absence of stress, men chose images unknowingly with the faces that resembled their own opposed to the participants under stress who preferred ‘different' women.   

According to Livescience, a science news site, Johanna Lass-Hennemann, a psychobiologist at the University of Saarland in Germany said, "Chronic stress is an important issue in today's society. In future studies, I would like to investigate the effects of chronic stress on our mating preferences and to do this in men and women."

Full study, "Effects of stress on human mating preferences: stressed individuals prefer dissimilar mates": http://rspb.royalsocietypublishing.org/content/early/2010/03/04/rspb.2010.0258.abstract