Science says you become more conceited when picking a life partner

Men and women will always choose potential partners based on how much their looks complements them, matching popularity and self-worth also matters too.

A person who's less attractive than their partner is bound to feel insecure and will always worry about their attractive mate for fear of losing them to someone else or infidelity.

Donaldson-Evans explains the reason behind this scientific theory:

Maybe you're a beauty queen and your sig-o isn't exactly a head-turner. Or maybe you're with a total hottie but you're more of a plain Jane. In either scenario, you might be looking at slightly rocky times ahead in the relationship. Experts say your best bet is being evenly matched with your mate in the looks department.

"Looks do matter and people do get attracted to potential partners based on matching for looks," says Jeanette Raymond, Ph.D., a licensed couples therapist and the author of Now You Want Me, Now You Don't!. "It's an evolutionary trait so that individuals are less likely to have a roving eye."

There's another biological explanation for why people tend to seek out partners who are equally good-looking that has to do with their future children.

"It's basically about having the best chance of offspring who are going to be fit, able to manage in the world and adaptable," Raymond says. "It's kind of like having the best genes you can think of."

A large-scale study of the so-called "matching hypothesis" — the theory that people choose romantic partners who are similar to themselves in a variety of ways — analyzed dating couples and found that they did pick each other based on similar looks. But even more important was that they had matching popularity and self-worth.

"Individuals voluntarily selected similarly desirable partners from the very beginning of the dating process," the authors wrote in the 2011 study "Out of My League," which appeared in the journal Personality and Social Psychology Bulletin. "Matching based on physical attractiveness becomes increasingly important at successive steps of dating."

If there is a difference in level of attractiveness between partners, it can cause friction.

"When there’s that kind of disparity between looks and physical attractiveness, there is an insecurity on the part of one of the partners," Raymond says. In other words, the less attractive person will feel insecure and worry that his more attractive mate might cheat on or leave him.

On the other hand, a looks discrepancy can make the more attractive one in the relationship feel safe.

"They go for these guys who are safe, but they still have those others who are salivating over them," Raymond says. "They get the best of both worlds. They still have the sense that they're desirable, but they also feel safe. And the guys aren't going to want to leave — they feel needed."

Men sometimes choose a less attractive partner because they want a mother figure, according to Raymond.

"One client married a woman who was not that attractive deliberately — he wanted something very pure and Madonna-like," she says (and by Madonna, she means the Virgin Mary, not the sexy pop star!).

Most of those polled about whether they were evenly matched with their partners looks-wise were coy and declined to answer. But one admitted that she and her husband are eerily similar in that department.

"My husband and I look like we're related," says Sharon Kehnemui. "And you should see my cousin and her wife. They look like twins. I assumed it was narcissism."

In the end, though an imbalance in physical attractiveness could prove to be an issue in a relationship, it doesn't have to be.

"The looks matter if you’re just wanting to be showing the world, 'Look what a catch I’ve got!'" Raymond says. "But it may not in terms of whether you have a good relationship and whether you’re going to last."