Monday, December 05, 2011

A gene that makes you appear to be kinder...

Kogan and colleagues at the Univ. of Toronto have examined some behavioral consequences of variations of the gene that codes for the receptor for the hormone oxytocin, since high levels of oxytocin are believed to make people more sociable. Volunteers (116) were asked to watch 23 brief silent videos that showed people with GG, GA, or AA versions of the gene responding to their partner telling them a story of personal suffering, and rate how kind and trustworthy the person in the video appeared to be. Those with the homozygous GG version of the oxytocin receptor gene were judged to be kinder than those with GA or AA versions, apparently because those with GG variations used significantly more non-verbal empathetic gestures in their storytelling such as smiling and nodding. Here is the abstract:
Individuals who are homozygous for the G allele of the rs53576 SNP of the oxytocin receptor (OXTR) gene tend to be more prosocial than carriers of the A allele. However, little is known about how these differences manifest behaviorally and whether they are readily detectable by outside observers, both critical questions in theoretical accounts of prosociality. In the present study, we used thin-slicing methodology to test the hypotheses that (i) individual differences in rs53576 genotype predict how prosocial observers judge target individuals to be on the basis of brief observations of behavior, and (ii) that variation in targets’ nonverbal displays of affiliative cues would account for these judgment differences. In line with predictions, we found that individuals homozygous for the G allele were judged to be more prosocial than carriers of the A allele. These differences were completely accounted for by variations in the expression of affiliative cues. Thus, individual differences in rs53576 are associated with behavioral manifestations of prosociality, which ultimately guide the judgments others make about the individual.


  1. A person can be genetically kinder? Is there any influence as far as upbringing or education that could be taken into account. If the subjects were picked at "random" the geographic and demographic influences could be taken into account. If the pool is from a small enough region with the exact same upbringing, then the genetic factor is determinate. Without all the data factored in, how can it be definitive? Great details and well done. Cheers.

  2. A bit more from the methods section:
    We recruited 116 undergraduates (52% female) from the University of Toronto Mississauga to serve as the observers. The observers were ethnically diverse: 36.2% Caucasian, 38.9% Asian, and 24.9% other ethnicities. Their age ranged from 17 to 23 y (M = 18.69 y, SD =1.16). Observers completed the study online.

    All targets were ethnically Caucasian, ranging in age from 18 to 33 y (M = 23.78 y, SD = 3.49). Given the small number of targets with the AA genotype and past work on rs53576 (10, 13, 14), all analyses focused on comparing targets homozygous for the G allele versus carriers of the A allele. No Asian targets were included in the study because previous research has demonstrated that variation in rs53576 may relate to different functionalities across ethnic groups (29). Furthermore, within the parent study from which targets were selected, very few of the Asian participants had the GG genotype, which would have made it difficult to test the hypotheses from the present study with Asian targets.