Have you ever wondered what first attracted you to your partner? Was it her sense of humor? His bulging biceps? Her smile? 

Actually, it was probably her resemblance to your mother — or his to your father. It turns out, your parents' appearance plays a large role in the appearance of the person that you look for in a mate.

Don't worry, I'm not going to go all Freudian and suggest that most boys want to marry their mothers and kill their fathers. But it does make sense that men look for women who have the same eye and hair color as their mother. 

The book, "In Your Face: The New Science of Human Attraction," takes a hard look at the real factors that affect our definitions of beauty and attraction. Author David Perrett found that parental appearance was one of the best indicators for the appearance of the person you will marry. As Perrett puts it, "If a man’s mum had blue eyes and his dad had brown eyes, then his partner was likely to have blue eyes, just like his mum." The mother's hair color had a similar effect on the hair color of the would-be spouse: "Similarly, the mother’s hair colour was the single best predictor of a male partner’s hair colour."

For women, it's a bit more complicated. A woman is likely to look for a man with similar features to her father — but only if she had a good relationship with her father. And it had more to do with quality of time spent with dad than quantity. Thus, even when a dad traveled a lot, if he was supportive and caring with his daughter when he was around, it influenced her choice in the appearance of her mate.

"The male face shapes to which a given woman was attracted bore a geometric similarity to the face shape of her father," notes Perrett. "What was really interesting was that this was found to be true only for daughters who had had a good relationship with their fathers during early childhood: when a woman got on well with her father, she was drawn to men who looked like him."

Using these characteristics as a guide, researchers were able to tell which men and women were married just by looking at photos of their parents — searching for a resemblance between the bride and the groom’s mother, or between the groom and bride’s father.

"These results show clearly that young adults form partnerships with individuals who resemble their opposite-sex parents. The guy marries a woman whose face looks like his mum’s, and the gal marries a man whose face looks like her dad’s."

Related on MNN:

There's a reason you look like your husband's mother
Like it or not, studies show that we choose prospective mates based on their resemblance to our parents.