Study finds people choose spouses with similar DNA
May 24 Shanghai Daily
People tend to choose spouses who have similar DNA, according to
scientists who reported yesterday the results of a study exploring the
genetic resemblance of married couples.The researchers examined the
genetic blueprints of 825 US married couples and found a significant
preference for a spouse with DNA similarities across the entire human
genome.
The study compared this affinity for husbands or wives with similar
DNA makeup to the well-established and strong tendency of people to
marry mates with similar educational levels. The researchers found that
the preference for a genetically similar spouse was about a third as
strong as the preference for a spouse with comparable education.The
1,650 people studied in the research were non-Hispanic, white men and
women born between the 1930s and 1950s who were taking part in a broader
US government-funded study involving health and retirement."We do know
in some sense that people prefer genetically similar spouses because we
know that people tend to date and marry within their own racial and
ethnic groups," said researcher Benjamin Domingue of the University of
Colorado's Institute of Behavioral Science, who led the study.
"We worked really hard in this study to not just replicate that
fact," Domingue added. "We eliminated racial variability and tried to
control for ethnic variability. And we still find a preference for
genetically similar individuals,"The researchers measured genetic
similarity by comparing 1.7 million individual DNA building blocks,
known as single nucleotide polymorphisms, in the study participants.They
compared the genetic makeup of married couples to other randomly chosen
people of the opposite sex in the same pool of study participants.A host
of things
Domingue said the actual mechanism for a person being drawn to
another person's genetic similarities is probably complicated and
multifaceted "just a whole host of things," he noted.The researchers
noted that people usually pick spouses with similar backgrounds and
characteristics in addition to education, including race, religion, age,
income and body type. Genetic similarity can be added to the list, they
said."For example, people clearly care about height in picking partners.
To the extent that tall people marry other tall people, that is going
to result in genetic similarity among spouses. But it is difficult to
know whether height or genes is driving this decision," Domingue
said.The researchers added that it would be interesting to see the
results of similar studies that involved other populations including
additional races, interracial spouses and gay couples.
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