The seven year itch? The four year slump? What about the one year nosedive? The real test of a relationship, at least for the man, may come after just 12-months according to scientists. British researchers at Worcester University found that after one year of a relationship, a man’s testosterone levels drops significantly. During the first year of the couple being together, the man’s hormone level is high. He is ready to fend off competitors so to be the only one for his lady love. He may also be ready to engage in other sexual experiences early on, in case this relationship doesn’t work out. But after a 12-month period his testosterone level falls significantly. 75 male participants between the ages of 18 and 39 took part in this study. Each was queried about his relationship status and how long it had lasted. Then the men’s testosterone levels were measured. Those in new relationships saw their hormone levels sink after one year’s time, researcher’s discovered. For those in relationships for much longer, their testosterone level plummeted even further, by one-third.
Dr. Daniel Farrelly led the study. He is a psychologist at the university’s Institute of Health and Society. Farrelly believes this may be a biological sign of certain external cues that the couple is expected to remain in a committed relationship. Another reason could be that less testosterone would make a man less aggressive, and so better at raising children and other aspects of fatherhood. Whether a man was single or in a relationship didn’t affect his hormone level. Only when he reached the year mark or beyond did he see his level drop. This adaptation may have helped men switch gears into becoming husbands and fathers instead of fighting off would-be competitors or scoping the scene for other females. The study was published in in the journal Evolutionary Psychology.