Are men with sisters sissies?

They say everything is bigger in Texas, and we think this theory might be a little larger than life - but here goes. If your brother has little to no luck with the ladies, there may be a good reason for it. A new study has shown that men who have grown up outnumbered in a family surrounded by females are viewed as "less sexy" by women as an adult.

The study, undertaken at the University of Texas, also said that men who grow up with a lot of female siblings will have less sex as adults. And how was this conclusion reached? By studying rats, of course.

According to reports, "The male rats who were raised solely with female rats - their "sisters" - were found to be less sexually active later on than the male rats who were raised with other male rats."

Apparently, in the company of rats raised among females, female rats didn’t exhibit their mating actions, meaning they weren’t keen to get down and dirty with the male rat.

Researchers believe this behaviour applies to humans as, "It tells you that families are important - how many brothers and sisters you have, and the interaction among those individuals ... Families are particularly important in shaping personalities. The environment where you were raised doesn’t determine personality, but it helps to shape it."