An alcoholic beverage makes men respond more to the smile of others in their social group, says a new study.
Lead researcher Catharine Fairbairn of the University of Pittsburgh, said that the experimental alcohol study, which included a social context, found the clearest evidence yet of greater alcohol reinforcement for men than women.
Fairbairn said that they wanted to explore the possibility that social alcohol consumption was more rewarding to men than to women, the idea that alcohol might actually 'lubricate' social interaction to a greater extent among men.
The team decided to focus on an objective non-verbal indicator of social bonding, examining the infectiousness of genuine smiles in drinking groups. Genuine, or Duchenne, smiles were associated with actual felt emotion as opposed to outward displays of emotion, which may or may not be genuine. Importantly, these smiles could be identified and measured using a standardized procedure.
The researchers randomly assigned 720 healthy social drinkers, ages 21 to 28, to groups of three. Each group was then randomly assigned to receive a particular drink: an alcoholic beverage (vodka cranberry), a non-alcoholic beverage, or a non-alcoholic "placebo" beverage that was described as alcoholic. The researchers smeared the glass of the fake alcoholic drink with vodka and floated a few drops of vodka on top of the drink to make it more believable.
The participants in each group were casually introduced and positioned around a table. The beverages were doled out in equal parts over time, and participants were told to drink them at an even rate. Otherwise, the participants weren't given any specific instruction and were allowed to interact freely.
Based on the video recordings, Fairbairn and colleagues used sophisticated analyses to model smiling behavior in the groups, following the spread of smiles from one individual in a group to the next.
They found that alcohol significantly increased the contagiousness of smiles, but only for all-male groups as it did not have a significant effect on emotional contagion for groups that contained any women. The findings suggested that alcohol is especially likely to induce a sort of "social bravery" among men, disrupting processes that would normally prevent them from responding to another person's smile.
Among groups who received alcoholic beverages, a smile was also more likely to be "caught" if those on the receiving end of the smile were heavier drinkers, regardless of gender.
Smiles that were likely to catch on were associated with increased positive mood and social bonding, as well as decreased negative mood. Thus, smile infection could represent an important indicator of alcohol-related reinforcement and a mechanism supporting drinking.
The study is published in Clinical Psychological Science, a journal of the Association for Psychological Science.