Why Are We Monogamous?
Over the years, researchers have tried to explain monogamy, but in efforts to find out how people maintain relationships, some researchers look at more subtle clues—literally.
Single, male subjects rated a woman the most attractive at the peak of her ovulation, scientists found, which is to be expected since that's when she's the most fertile. On the other hand, male subjects in a committed relationship behaved the opposite by giving the woman lower attractive marks during her fertility peak. Although it's been thought that women expertly conceal their ovulation cycles, some studies suggest that might not be the case. During ovulation, women's voices and appearance may seem more attractive to men.