In Brief

The three-martini business lunch may be on the wane, but it's still fairly common for co-workers to talk shop over a beer. Previous research has found that moderate alcohol consumption can relax drinkers and promote an open exchange of ideas, but a new study finds drinking in groups may also make a group more competitive and focus group members' attention on the task at hand. The research appears in the June issue of Psychology of Addictive Behaviors (Vol. 21, No. 2).

Researchers led by Timothy Hopthrow, PhD, a psychologist at the University of Kent in England, recruited 158 university students and randomly assigned most of them to one of 30, four-person experimental groups. The remaining students participated in the study as individuals. Participants were asked to drink either an alcoholic beverage that raised their blood alcohol content to the legal English driving limit (.08 percent) or a placebo beverage.

Then the researchers asked them to play a multiple-trial prisoner's dilemma game with monetary payoffs. The game required that the participating groups or individuals make either cooperative or uncooperative choices against an opponent. Players could increase their own gain on a particular trial by competing, but both pairs of the game would benefit most if they persistently cooperated. The opponent always made the first move, which was cooperative, and the researchers recorded how likely individuals and groups would be to cooperate in return or to start competing.

The researchers found that lone individuals showed the same level of cooperation regardless of whether they'd been drinking, and that non-drinking groups were just as cooperative as individuals. However, when groups had been drinking, they became significantly more competitive, says Hopthrow, perhaps because group members shifted their focus from the collective welfare of all players in the game to the immediate gains for their group.

The researchers caution that alcohol can also make a group behave in a more extreme or dramatic way. "In addition to competition, this could affect things like expressions of prejudice or expressions of affection," notes researcher Dominic Abrams, PhD, a social psychology professor and director of the Centre for the Study of Group Processes at the University of Kent.