Lead author Ash Levitt -- a post-doctoral fellow at the University at Buffalo's Research Institute on Addictions and M. Lynne Cooper of the University of Missouri -- says the study included 69 heterosexual couples, average age 20-21, most white and more than 90 percent college students. Most were dating seriously and seven of the couples were married.
The researchers say the beneficial outcomes for relationships were associated with relatively lower levels of drinking -- one to three drinks. However, harmful outcomes such as decreased intimacy and increased relationship problems were associated with heavier levels of drinking -- four or more drinks.
"The harmful effects of heavy drinking were buffered when partners drank together versus apart," Levitt says in a statement. "Also, when both partners drank either heavy or light amounts, as long as they were similar amounts compared to their partner, it was better for the relationship than when one drank heavily and the other lightly."
The study was published in the Personality and Social Psychology Bulletin.