FRIDAY, July 29, 2005 (HealthDay News) -- Love and friendship may have genetic roots, according to a study in twins that suggests DNA has a strong influence who individuals marry and pal around with.
The study of several hundred pairs of identical and fraternal twins found that individuals tend to share trait similarities with their spouses and close friends -- similar to what might be found in a non-identical twin brother or sister.
Researchers at the University of Western Ontario in London, Canada, also found that the spouses of identical twins (who share 100 percent of their genes) were more similar to their mate than were the spouses of fraternal twins (who share about 50 percent of their genes). The same finding was true for the best friends of twins.
For this study, the twins and their spouses and friends filled out a 130-item questionnaire that collected information about their social background, personality and attitudes.
The findings support the evolutionary psychology theory that genetic similarity influences individuals' selection of mates and other close relationships.
"If you like, become friends with, come to the aid of, and mate with those people who are genetically most similar to yourself, you are simply trying to ensure that your own segment of the gene pool will be safely maintained and eventually transmitted to future generations," the study authors wrote.
The study appears in the July issue of the journal Psychological Science.
More information
Learn more about how genes influence health and behavior at the National Human Genome Research Institute
