A new theory suggests evolutionary dispersal patterns have influenced the genes that determine our social behavior.
Researchers from Oxford University and the University of Tennessee, Knoxville, examined the impact that genes knowing which parent they come from — a process scientists call “genomic imprinting” — has on how selfish or altruistic they want their carriers to be.
Historically, women moved around geographically more than men, and so are less related to their neighbors.
Consequentially, the researchers suggest that our paternal and maternal genes are in conflict over how we should behave. The scientists believe that our paternal genes encourage us to be more altruistic while our maternal genes encourage us to be more selfish.
“When women disperse more during their lifetime than men, as seems to be the case for ancestral humans, this leads to you being more related to your neighbors through your father than through your mother,” said Dr. Andy Gardner of Oxford University’s Department of Zoology.
The genes you receive from your father are telling you to be kind to your neighbors, whereas the genes you receive from your mother may encourage you to act more selfishly.
Mutations in imprinted genes have previously been linked to growth disorders in infants and, more recently, it has been suggested that they could underpin neurological disorders such as autism and psychosis.
This study reveals how such disorders of the social brain can evolve by mutations favoring the expression of paternal genes (favoring altruism) or maternal genes (favoring selfishness).
“What our research reveals is that the popular idea of someone battling their psychological ‘demons’,” noted Dr. Gardner, “that are telling them to behave in a selfish way, has some basis in our genetic makeup — we are all coalitions of conflicting genes.”
A report of their research is published in the journal Evolution.
Source: Oxford University