Researchers at the University of Trier in Germany and Wake-Forest University in the U.S. did a study on a group of heterosexual men.
The mens’ hands were placed in warm and then unbearably hot water. Their biometric responses were measured as the men looked at images of women while in this stressed and relaxed state.
The study concludes that "stress affects human mating preferences: unstressed individuals showed the expected preference for similar mates, but stressed individuals seem to prefer dissimilar mates."
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."
In general, stressed men preferred women who were not like them. On the other hand, calm men selected partners that most resembled them.
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."