In a study out Monday in the Proceedings of the National Academy of Sciences, researchers looked at prairie voles, one of the few animals that engage in longterm monogamous relationships and one that has proved to have the same kind of neurochemical responses that humans have during social interactions.
Appropriately for this kind of study, they love to drink alcohol and encourage each other to drink.
‘They’re party animals,” said Dr. Larry Young, a professor of psychiatry at Emory University and Yerkes National Primate Research Center. “They drink a lot more than mice. Also, when they are together they drink more. The amount of alcohol they drink is related to how much their partner drinks. They are social drinkers as well.”
But after drinking during 24 hours of cohabitation, males were less likely to choose their partner again compared to males that drank water, but the opposite was true for females.
“If they are both drinking and they happen to be engaging in behaviors that would promote a pair bond, the females are more likely to develop that bond,” Young said. “They’re more likely to become attached with alcohol. It’s as though the alcohol is activating, greasing those neurochemical circuits that are involved in formation of an attachment. Whereas for the male, it doesn’t seem to be at all, at least not for the attachment part.”
Attraction and addiction appear to be very similar in the brain and can use some of the same areas and transmitters, said Dr. Karen L. Bales, an Augusta native who is now the vice chairwoman of psychology at the University of California, Davis. She was not involved in the study but is familiar with the research.
“It’s been suggested that love and addiction share the same neural systems (you then become ‘addicted’ to the person you love),” she said in an e-mail. “Given the different ways that men and women relate to drugs of abuse, and to relationships, it’s probably not surprising to see sex differences in how the drugs of abuse affect relationships. We should of course be careful in directly extrapolating to humans.”
Young also is cautious about making a direct comparison to humans but noted that if one did “it would suggest that a couple drinking, having a good time, it would mean that the female would be more likely to develop these attachments to that male where the male would be seeing it more as a physical interaction and not develop the attachments afterward, which can be destructive.”
Two of the main chemicals involved in attachment in humans, oxytocin and vasopressin, do not appear to be affected by the drinking. Instead, it is chemicals related to anxiety that the drinking seems to lessen. The less-worried male then is less likely to pair up, while the less-anxious female appears to be more attracted.
The most important part is that these animals are not being affected by social convention or cultural expectations as humans might be, Young said.
“The animals are driven really by these neurochemical events,” he said.