NewScientist.com, Apr. 28
Women tend to choose husbands who look like their fathers — even if they are adopted, reveals a new study.
The research shows that women use their dads as a template for picking a mate by a process called “sexual imprinting”, says Tamas Bereczkei at the University of Pécs in Hungary and colleagues.
Husbands and wives have long been suggested to look alike and this is known to occur in many animal species. Couples that look like each other are also more likely to share common genes, and having a degree of similarity is believed to beneficial.
This might explain the study’s findings, suggests Glenn Weisfeld, one of the research team and a human ethologist at Wayne State University, Detroit, US “There seems to be an advantage for animals to select a mate somewhat similar to themselves genetically,” he told New Scientist.
“One good possibility is that there are some fortuitous genetic combinations which are retained in the offspring if both parents are similar,” he says. “In humans there is evidence to show a lower rate of miscarriage.”
However, he points out that there is a balance between the benefits of marrying someone genetically close and the harmful effects of inbreeding. “There seems to be an ideal balance, maybe around the first or second cousin point.”
Imprinting is a fast, instinctive form of learning, perhaps best known from the phenomenon in which newborn ducklings bond with the first object they see.
To test whether women use imprinting to base their marital choices on the appearance of their fathers, the researchers took 26 adoptive families and examined how alike various family members looked. Using adoptive families meant inherited preferences could be ruled out.
Nearly 250 students were asked to rate similarities within three sets of photos. The first showed photos of the wife and four possible husbands, one of whom was the real spouse.
The second showed a photo of the adoptive father as he would have looked when his daughter was between two and eight years of age, and the possible husbands. The third set showed the adoptive mother and the four possible husbands.
The students correctly matched husbands and wives significantly more than they would have by chance alone. But the similarity between husbands and adoptive fathers was most striking. Where the judges might have matched a quarter of the husbands with the fathers by chance, they actually matched 38 per cent correctly.
There was no significant resemblance between the husband and the adoptive mother.
An “unexpected” finding, says Weisfeld, was that fathers who were judged by their daughters to have showed the most emotional warmth were much more likely to have son-in-laws who looked like them.
“Our results support the notion of a long-lasting effect of attachment during childhood on later mating preferences,” the team concludes. They suggest that people form a “mental model” of their opposite-sex parent’s appearance, which they then seek out in later life.
But Weisfeld points out that mating decisions are complex in humans and many other biological and social factors will play a part. For example, studies have shown that a person’s smell can also help someone judge how related they are to a potential partner.
Journal reference: Proceedings of the Royal Society of London B (DOI: 10.1098/rspb.2003.2672)