A positive match may bring about “the test says we’re compatible so we obviously are” thinking even if there are red flags indicating otherwise, leaving couples to remain in relationships they might abandon in different circumstances, whereas a low score may create or reinforce doubts in an otherwise solid relationship.
Most importantly, genetic affinity matching is a test case for what will be an increasingly prevalent challenge as we enter the era of widespread whole genome sequencing.
As one scientific review of the entire body of data concluded, “the mixed evidence …
makes it difficult to draw definitive conclusions, [but] the large number of studies showing some MHC involvement suggests there is a real phenomenon that needs further work to elucidate.” Into this complicated field now come direct-to-consumer genetic testing companies such as Instant Chemistry and Singld Out.
A large number of studies, involving different experimental methods and populations, have now been reported, and they give discordant results.
While some research has supported the theory that MHC gene diversity drives human attraction, other studies have reported different or conflicting results.
DNA results become part of each user’s profile, and members can search for and evaluate potential matches based on their genetic compatibility.
Instant Chemistry and Singld Out are not the first to promote genetic testing to determine romantic compatibility.
Yet, as noted above and as is common for most genetic research, especially as it relates to complex human behaviors such as love and romance, the data supporting genetic attraction is highly inconsistent.
Singld Out claims that genetic tests can identify up to 40 percent of the chemistry of attraction between two people.
While not denying that genes play some role in mate selection, Mike Dougherty of the American Society of Human Genetics contends that the research to date does not support quantifying the impact of genetic attraction.
In 2008, a company called Gene Partner began to offer genetic testing to identify relationship compatibility.
Applying a similar concept are “pheromone parties” in which singles sniff well-worn T-shirts worn by members of the opposite sex to facilitate biological matches based on pheromones, the elusive compounds of attraction.
A leading hypothesis is that such “disassortative” mating will produce offspring with greater diversity in their MHC genes that will protect them against a broader range of pathogens.