"Long before it's in the papers"
November 14, 2011

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Gene found linked to easily visible differences in kindness

Nov. 11, 2011
Courtesy of Oregon State University
and World Science staff

A gene var­i­ant that af­fects em­pa­thy, pa­ren­tal sen­si­ti­vity and so­cia­bil­ity is so pow­er­ful that strangers watch­ing 20 sec­onds of si­lent vi­deo can tell apart peo­ple who have it, a study has found.

Sci­en­tists vid­e­otaped 23 ro­mantic cou­ples while one of the part­ners de­scribed a time of suf­fer­ing in their lives. The other part­ner’s react­ion through body lang­uage alone was the fo­cus of the stu­dy. Groups of strangers viewed the vid­e­os and were asked to rate the per­son on traits such as how kind, trust­wor­thy, and car­ing they thought the per­son was.

“Our find­ings sug­gest even slight ge­net­ic varia­t­ion may have tan­gi­ble im­pact on peo­ple’s be­hav­ior, and that these be­hav­ioral dif­fer­ences are quickly no­ticed by oth­ers,” said Alek­sandr Ko­gan of the Uni­vers­ity of To­ron­to, the stu­dy’s lead au­thor.

The work built on pre­vi­ous re­search by Sa­rina Ro­drigues Sat­urn of Or­e­gon State Uni­vers­ity and col­leagues, who linked a ge­net­ic varia­t­ion to em­pa­thy and stress re­ac­ti­vity. Sat­urn is sen­ior au­thor of the new stu­dy, pub­lished in the lat­est is­sue of the jour­nal Pro­ceed­ings of the Na­tional Acad­e­my of Sci­ences. The re­search­ers stud­ied ge­net­ic varia­t­ions that af­fect trans­mis­sion with­in the brain and body of a hor­mone known as ox­y­to­cin, which is linked to trust and rela­t­ion­ships. 

“It was amaz­ing to see how the da­ta aligned so strong­ly” with the var­i­ants, Sat­urn said. “It makes sense that a gene cru­cial for so­cial pro­cess­ing would yield these find­ings; oth­er stud­ies have shown that peo­ple are good at judg­ing peo­ple at a dis­tance and first im­pres­sions really make an im­pact.”

Be­fore re­cord­ing the vid­e­os, the sci­en­tists iden­ti­fied the cou­ples’ gene types as GG, AG, or AA through tests. The first type marks peo­ple with two cop­ies of a gene var­i­ant called G; the sec­ond, those with one copy of the G and one copy of the A var­i­ant; and so forth. Ac­cord­ing to pre­vi­ous re­search, GG peo­ple tend to act in a more car­ing way, where­as the oth­er two types tend to have a high­er risk of au­tism and self-re­ported low­er lev­els of pos­i­tive emo­tions, em­pa­thy and pa­ren­tal sen­si­ti­vity. Ox­y­to­cin has al­ready been linked with so­cial af­filia­t­ion and re­duc­tion in stress. It is as­so­ci­at­ed with so­cial rec­og­ni­tion, pair bond­ing, damp­en­ing neg­a­tive emo­tion­al re­sponses, trust and love.

Out of the 10 peo­ple who were marked by the neu­tral ob­serv­er as most em­path­ic, six were GG car­ri­ers; while of the 10 peo­ple who were marked as “least trust­ed,” nine were car­ri­ers of the A ver­sion of the gene, the re­search­ers re­ported. These peo­ple were viewed as less kind, trust­wor­thy and car­ing to­ward their part­ners.

What’s un­known is pre­cisely how the gene af­fects the be­hav­ior. The variant does lead to diff­erences in re­cep­tors, or mole­cular struc­tures, in­volved in oxy­tocin trans­mission.

How­ev­er the mechanics of it may turn out to work, Sat­urn be­lieves peo­ple can and do over­come their genes. “These are peo­ple who just may need to be coaxed out of their shells a lit­tle,” she said of the “A” car­ri­ers. “It may not be that we need to fix peo­ple who ex­hib­it less so­cial traits, but that we rec­og­nize they are over­com­ing a ge­net­ic­ally in­flu­enced trait and that they may need more un­der­stand­ing and en­cour­age­ment.”

Ko­gan said that many fac­tors ul­ti­mately in­flu­ence kind­ness and coop­era­t­ion. “The ox­y­to­cin re­cep­tor gene is one of those fac­tors – but there many oth­er forc­es in play, both ge­net­ic and non-ge­net­ic,” he said. “How all these pieces fit to­geth­er to cre­ate the co­her­ent whole of an in­di­vid­ual who is or is not kind is a great mys­tery that we are only be­gin­ning to scratch.”

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A gene variant that affects empathy, parental sensitivity and sociability is so powerful that strangers watching 20 seconds of silent video can tell apart people who have it, a study has found. Scientists videotaped 23 romantic couples while one of the partners described a time of suffering in their lives. The other half of the couple and their physical, non-verbal reactions were the focal point of the study. Groups of strangers viewed the videos and were asked to rate the person on traits such as how kind, trustworthy, and caring they thought the person was. “Our findings suggest even slight genetic variation may have tangible impact on people’s behavior, and that these behavioral differences are quickly noticed by others,” said Aleksandr Kogan of the University of Toronto and the study’s lead author. The study builds on previous research by Sarina Rodrigues Saturn of Oregon State University and colleagues, who linked a genetic variation to empathy and stress reactivity. Saturn is senior author of the new study, published in the latest issue of the journal Proceedings of the National Academy of Sciences. The researchers studied genetic variations that affect transmission within the brain and body of a hormone known as oxytocin, which is linked to trust and relationships. “It was amazing to see how the data aligned so strongly” with the variants, Saturn said. “It makes sense that a gene crucial for social processing would yield these findings; other studies have shown that people are good at judging people at a distance and first impressions really make an impact.” Before recording the videos, the scientists identified the couples’ gene types as GG, AG, or AA through tests. The first type marks people with two copies of a gene variant called G; the second, those with a copy of the G alongside a copy of the A variant; and so forth. According to previous research, GG people tend to act in a more caring way, whereas the other two types tend to have a higher risk of autism and self-reported lower levels of positive emotions, empathy and parental sensitivity. Oxytocin has already been linked with social affiliation and reduction in stress. It associated with social recognition, pair bonding, dampening negative emotional responses, trust and love. Out of the 10 people who were marked by the neutral observer as most empathic, six were GG carriers; while of the 10 people who were marked as “least trusted,” nine were carriers of the A version of the gene, the researchers reported. These people were viewed as less kind, trustworthy and caring toward their partners. “The oxytocin receptor gene in particular has become of great interest because a select number of studies suggest that it is related to how prosocial [empathetic] people view themselves,” Kogan said. “Our study asked the question of whether these differences manifest themselves in behaviors that are quickly detectable by strangers, and it turns out they did.” What’s unknown is precisely how the gene affects the behavior. However that may turn out to work, Saturn believes people can and do overcome their genes. “These are people who just may need to be coaxed out of their shells a little,” she said of the “A” carriers. “It may not be that we need to fix people who exhibit less social traits, but that we recognize they are overcoming a genetically influenced trait and that they may need more understanding and encouragement.” Kogan said that many factors ultimately influence kindness and cooperation. “The oxytocin receptor gene is one of those factors – but there many other forces in play, both genetic and non-genetic,” he said. “How all these pieces fit together to create the coherent whole of an individual who is or is not kind is a great mystery that we are only beginning to scratch.”