CNN-- Let's face it - everyone isn't nice. In fact, being nice is more difficult for some people than others. But is it possible that "niceness" is predetermined by our genes?
A new study in the journal Psychological Science suggests this: If you think the world is full of threatening people, you're not going feel compelled to be generous by doing things like volunteering and donating to charity. But if you have certain gene variants, you're more likely to be nice anyway.
Now hold on a minute - this doesn't give your mean neighbor an excuse to blame his DNA for not letting kids on the block play on his lawn.
It's a little more complicated than that.
The research: A few questions and some spit
Researchers offered an online survey to participants asking questions like:
–Do people have a duty to pay taxes?
–Are people basically good or bad?
–Do you engage in charitable activities?
Then some participants sent in samples of their saliva so researchers could check out their DNA. A total of 348 U.S. residents were included in the final analysis.
Researchers analyzed the spit samples. They looked at the particular variants of receptor genes these people had for the hormones oxytocin and vasopressin.
In case you're wondering, oxytocin and vasopressin are very similar structurally, and seem to have some similar social effects. For example, they're both associated with pair bonding - aka bringing closer together two spouses or a mom and her child.
In fact, that's why oxytocin has been called "the cuddle hormone."
But while the hormones have similar effects on the brain, they differ in the rest of the body. Oxytocin can induce labor. Vasopressin increases when you're thirsty and prevents the formation of urine.
As the authors of the new study expected, people who see the world as a threatening place tended to not engage in charitable activities - except if they had particular variants of the receptor genes that the researchers were looking for.
It turns out that if the receptors are especially sensitive to oxytocin and vasopressin, even people who fear others in society will do nice things, said Michael Poulin, assistant professor of psychology at the University at Buffalo and study co-author.
"We’ve found that these genes also predict people’s willingness to be nice on behalf of other people or aggressive on behalf of other people," Poulin said. In other words, such biological factors may influence your willingness to defend someone else.
That is consistent with other research, which found that rat mothers are more willing to be aggressive on behalf of pups when they received oxytocin.
Previous research has also shown that these hormones make people more socially active.
Blame the DNA?
Keep in mind that this study only shows associations between genes, hormones and behavior, and doesn't prove direct causal links.
It's not a "blame your DNA" situation, Poulin said.
"While we found some interesting interactions with genes and perceptions of the world, I would resist saying that we found genes that control behavior," he cautioned.
The next step for this area of study is to look at how sensitive people are to different kinds of threats.
A few questions that might be posed by future researchers:
–Is it important for people to believe they're helping good people?
–Is there something in a person's background or upbringing that influences how threatening they believe the world is?
Poulin and colleagues will also look at what other behaviors these genes might influence.
So it's probably a little too early for mean people to start using their DNA as a convenient excuse for their bad behavior. But maybe someday...
Post by: Elizabeth Landau - CNN.com Health Writer/Producer
Filed under: Genetics • Psychology