Why We're Strangely Attracted To People Who Look Like Us, According To Research

Do you and your partner ever get mistaken for siblings?

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According to researchers in an issue of Personality and Social Psychology Bulletin, we are attracted to people who resemble our parents or ourselves. In one study subjects were shown pictures of strangers which were preceded by a short glimpse of either their opposite-sex parent or a stranger.

Subjects exposed to a short glimpse of their parent before being exposed to the target picture were more likely to assign higher ratings of attractiveness to the person in the target picture.


Are we attracted to people who look like us?

In a second study, a picture of the stranger was morphed together with a picture of themselves or a picture of another stranger. When subjects were asked to rate the portrayed people for attractiveness, they usually picked the people who were an amalgamation of a stranger and themselves.


The findings in these studies go against the common saying that opposites attract. As it turns out, we are much more likely to fall for someone who looks like us or our opposite-sex parent.

This may indicate that taboos are social constructs instituted to prevent people from following their instincts. However, there are other explanations for why we are attracted to people who look like us.

Researchers at the deCODE Genetics company in Reykjavik reporting in an issue of Science found that marriages between third or fourth cousins in Iceland tended to produce more children and grandchildren than those between completely unrelated individuals.

The researchers suggest marrying third and fourth cousins is optimal for reproduction because this degree of genetic similarity yields the best gene pool.

Sibling and first-cousin couples could have inbreeding problems, whereas couples far removed from each other could have genetic incompatibilities. Third and fourth-cousin couples are genetically compatible while having no serious inbreeding problems.


At first glance, these findings may seem to go against the so-called Westermarck effect. In a series of studies Edvard Westermarck, a Finnish Anthropologist, found that people who grow up together are disposed not to fall in love with each other after they reach maturity.

The Westermarck effect, however, is completely consistent with the findings cited above. Living in close proximity is no doubt the decisive factor for desensitization in terms of attraction, not the degree of resemblance.

In fact, the Westermarck effect has been confirmed in the Israeli kibbutz system where people who grow up together often are not directly related to each other.

Sim Pua marriages in Taiwan also confirm Westermarck’s theory. “Sim pua” means “little daughter-in-law”. A female infant is given to a family to be reared as a daughter by the family. When she grows up, she is to marry a son in the family. Sim Pua marriages have a low fertility rate, a high divorce rate, frequent adultery, and a lack of attraction. In some cases, the son or daughter-in-law refuses to marry their destined spouse.


Berit “Brit” Brogaard, D.M.Sci., Ph.D., is a professor of philosophy and Director of the Brogaard Lab for Multisensory Research at the University of Miami. Her work has been featured on MSNBC, Daily Mail, TIME, Psychology Today, and ABC News.