Have you ever wondered why alcohol makes women all touchy and clingy? Or why drunken men may cheat on their girlfriends? If so you’ll probably love this study performed by scientists from the Oregon University (USA). They checked out what happened when they offered alcohol to couples of prairie voles. These small rodents are known to be extremely faithful. Once they have chosen a life partner they stick to a lifestyle of complete monogamy. For that reason they are often used for social monogamy experiments. In this experiment with young couples it turned out that the female voles wanted to cuddle more when drunk, where the their male partners got in the mood to stray and try new partners.
The scientists in Oregon put young couples of prairy voles (male and female) together. Both at that time in the experiment were still in search of a life partner. They were open to ‘bonding rituals’ like cuddling and mating. The rodents then got the choice between water and a mix of water and ethanol, similar to vodka. For 24 hours they were left alone. As expected the voles had no interest in staying sober and had themselves a little party. The study report states: “We previously demonstrated that prairie voles voluntarily self-administer substantial amounts of alcohol (ethanol) and can influence the drinking patterns of a social partner, similar to social drinking in humans.”
After the 24 hours all voles in the experiment were pretty wasted. More than half the times they went to drink they chose the booze. They consumed enough alcohol that their bodies contained 12,5 grams of it on 1 kilo body weight. To compare: most full grown men would have to drink 2 bottles of vodka or more to achieve this, respect!
Anyway, after their alcohol infused 24 hours together the voles were seperated for the so called ‘partner preference test’, that was used before but without alcohol. During this test the voles were introduced to potential new partners for periods of 3 hours and were then reintroduced to the partner they got drunk with. Kind of like a dating show they then had to chose a partner. It’s important to say that during the 24 hours the drunk couples mated with the same frequency as the sober ones. So any reactions later in the experiment couldn’t be traced back to the quantity of sex. Also good to know: the scientists found no evidence that any drunk behaviour (agression, stumbling or passing out) played any role in matchmaking process.
So what happened when the voles were introduced to new partners? Where the sober females in 2/3rd of the cases stayed with their original partner and 1/3rd tried a new lover, nearly a stunning 100% of the drunk female voles stayed with the man they partied with. That’s right, while drunk they chose their partner for life. The male voles behaved in quite the opposite way. All the sober ones stayed with their original partners, as where a lot of drunk males tried to avoid their former lovers (who were in the mood to cuddle) and showed more interest to the new strangers .
To explain the voles’ behaviour the scientists then sacrificed 2 sets of 9 pairs (male and female, sober and intoxicated) of rodents to examine their brains. They found that alcohol affected the neuropeptide systems in their brains, the area’s that influence social behaviors and anxiety. In the brains of the males it increased the density of fibers in the amygdala, which is a sign of reduced anxiety. In females the opposite happened as alcohol promoted anxious feelings. This may explain why the drunk girls chose their safe first love, where the relaxed males felt great and in no mood to commit to a partner yet.
Although we can’t copy the behavior of voles directly onto humans there is a clear resemblance between the social behavior of our ‘labrats’ and people when they go out to party. But scientists also state that the way we act is not just a biological reaction, since humans have the ability to control or change their actions. So clingy women and cheating men still can’t use alcohol as a valid excuse for their behavior.