CTVNews.ca Staff
Published Saturday, Sep. 1, 2012 7:05AM EDT
Are women genetically programmed to have sunnier dispositions than men? Some U.S. researchers think they might.
Scientists with the U.S. government’s National Institutes of Health, the University of South Florida and elsewhere think they have narrowed in on one of the genes that fuels happiness. But it seems the gene only has an effect in women, not men.
The researchers found the gene after analyzing the DNA of 193 women and 152 men, who were asked to score their own levels of happiness. Women with low expression of the MAO-A, or monoamine oxidase-A gene, reported much more happiness than those with no expression.
That finding was made after the researchers controlled for other factors that can affect happiness, such as income and education level. Interestingly, though, the researchers found no link with the gene in men.
The MAO-A gene works similarly to antidepressant medications: it regulates the activity of an enzyme called monoamine which breaks down "feel good" neurochemicals, such as serotonin and dopamine. A dysfunctional MAO-A gene has been linked to increased aggression levels in both mice and humans.
Lead author, Dr. Henian Chen, an associate professor in the Department of Epidemiology and Biostatistics at USF, says he was surprised that low expression of this gene was linked to greater happiness in women.
He notes that low expression has actually been linked to psychological problems such as alcoholism, aggressiveness and antisocial behavior.
"It’s even called the warrior gene by some scientists. But, at least for women, our study points to a brighter side of this gene," he said in a statement.
Chen thinks that the low-expression version of the MAO-A gene promotes higher levels of monoamine, which allows larger amounts of these neurotransmitters to stay in the brain and boost mood.
While many of the men studied carried a copy of the "happy" version of the MAO-A gene, they reported no more happiness than those without it.
Chen and his colleagues suspect that might be because men have higher levels of testosterone, which might cancel out the positive effect of MAO-A on happiness in men.
Of course, there’s a lot more to happiness than genes. In fact, studies conducted on twins estimate that genetic factors account for only 35 to 50 per cent of the variance in human happiness.
Chen says more research will be needed to identify which genes influence resilience and well-being.
The findings appear online in the journal Progress in Neuro-Psychopharmacology & Biological Psychiatry.
