You’ve probably met a couple or two who look like they could be siblings. Or perhaps you’ve been told that by people you’ve encountered. Sure, it seems weird or oddly cute, but science confirms there are a few reasons why this happens with people who have been together for a long time.

Well, we all want compatibility in our relationships, but some couples are on another level when it comes to the mating game. Their faces look similar, and some may even take on the same mannerisms. Here we highlight some of the scientific reasons for these quirky pairings.


  1. You Favor Your Parents’ Looks

    Whether we realize it or not, many people subconsciously choose mates who favor their parents. Men and women tend to be attracted to mates that resemble the parent of the opposite sex. Called sexual imprinting, it’s a process that causes a person form a mental image of their ideal mate based on the parent who raised them. Studies show that it can occur in biological and adoptive families.

  2. Self-Love

    Another way the subconscious plays a role is in assortative mating: choosing someone who looks like you. People will be attracted to mates who have a similar height, behavior, physical build, facial appearance, and ethnicity as themselves. Further studies have even shown that with assortative mating, partners are also chosen if they have the same educational and income background.

  3. Shared Genetics

    Several recent studies by American universities – including one published to PLOS Genetics journal – demonstrate that people marry those with the same genetic ancestry.

    For those of Northern/Western European, Southern European, or Ashkenazi Jewish lineage, a pattern was discovered in how they chose their spouses. Across three generations, people married mates with the same ancestral/genetic traits.

  4. Mimic and Mirror

    Perhaps one of the most well-known studies is a 1987 one conducted by Robert Zajonc and his team on convergence in appearance. Married couples had their pictures taken at the beginning of their unions and then 25 years later.

    It was learned that after so many years, they began to mirror each other’s facial expressions and mannerisms through a process called convergence. Some couples could even sound alike!

  5. Empathetic Aging

    The Zajonc study also revealed that couples who were happier also shared the most resemblance in the face. Similar smile lines, creases, and contours were seen between husbands and wives who lived together for a long time.

    Sharing the same emotional experiences or being empathetic towards a partner’s experiences create similar features in the face – like wrinkles.

Though there are a combination of factors that draw people together when it comes to love, what seems random may not be so random after all. If you’ve ever cringed at the idea that you were dating your mother or father, now you can be assured that there is scientific merit to that notion.

How many couples do you know who resemble each other? What are your thoughts on having a look-alike partner? Do you look, act, or sound like your partner?