Friday, April 08, 2011

GG Alleles & Empathy


'The Genetic Basis of Empathy' by Maya Sen (Berkley Science Review Fall 2010, p. 10)

"Like all proteins, the blueprint for the oxytocin receptor is coded in our genes. Slight variations in this genetic sequence can lead to significant differences in the shape of the protein, which has dramatic effects on its functionality. In this case, a mutation at a single point in the genetic sequence—an adenine (A) in place of a guanine (G)—affects how oxytocin interacts with its receptor. In other words, there exist two forms of the oxytocin receptor gene, A and G alleles. Since one copy of the gene is inherited from the mother and another from the father, individuals possess either two copies of the G or A allele (GG or AA homozygous), or a combination (AG/GA heterozygous). Previous research has found that AA homozygous individuals are more likely to be diagnosed with autism, a social impairment disorder.

Rodrigues and Saslow, curious to what extent genetic variation correlates with empathy, measured empathic behavior using RMET in 192 UC Berkeley undergraduate students. Along with a self-reported exam to probe empathy, students provided DNA samples to test for the genetic variation. They found 25 percent of UC Berkeley students GG homozygous regardless of gender, while the rest either had one or two copies of the A allele. Individuals with the G allele scored 23 percent higher on the RMET, indicating they were more likely to identify the correct emotions shown in each snapshot. Even in the self-reported exam, GG individuals showed a higher level of disposition toward empathic behavior than AA/AG participants. They found that parental care and the individual's home environment had little influence on their results."

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