This is the blog for Yale's undergrad course ANTH204:
An introduction to the patterns and processes of human genetic variation. Topics include: human origins and migration; molecular adaptations to environment, lifestyle and disease; ancient and forensic DNA analyses; and genealogical reconstructions.
Tuesday, November 15, 2011
The OXTR Gene and Human Behavior
OXTR has a remarkable effect on the way we interact with and relate to our fellow man. This oxytocin receptor gene codes for a protein which acts as a receptor for oxytocin, a hormone and neurotransmitter. The OXTR gene may govern behavioral modulation and induce emotions almost immediately detectable by humans. On human chromosomes at the 3p25 location, the OXTR gene encodes these proteins.
So why are OXTR genes so special?
There are two types of OXTR, the A and G, which designate how the OXTR affects our social behavior. With two G-type OXTR genes, a human tends to exude more empathy and sensitive behavior. Those with one or more A-copies are less likely to exhibit these empathic or sociable tendencies. Aleksandr Kogan's study at the University of Toronto has found that the difference between these two types of OXTR genes is what constitutes the difference between two very different dispositions among people-- which strangers can sense within just minutes of meeting or watching an individual.
It's fascinating to consider that our behavior is so closely determined by our genome. Kogan's work filming individuals talking to a partner about suffering has revealed that, when volunteers watch the footage on mute for just 20 seconds, those volunteers responded almost precisely according to whether they had A or G-type OXTR genes. G-owners tended to respond more empathically, while A-owners, as expected, did not respond as emotionally.
In addition, independent viewers of the clips with two G-copies responded to the footage with a more physical empathy: eye contact, open arms, nodding heads, etc. As a result, these viewers may be perceived as more trustworthy, social, or emotionally in-touch than others. This shows that people are incredibly sensitive to behavior as a social cue. A tiny genetic difference actually manifests in human behavior, even for mere seconds, as a huge effect on personality and sociability.
Kogan worked with a strikingly small sample size, which is why his paper has been largely criticized by other scientific scholars. However, it provides an exciting window onto the genetic underpinnings of human behavior.