For every cup size in each of the three tasks, students overestimated how much fluid they would need for a "standard" drink size. "Regardless of which type of drink we asked students to pour," said White, "they almost always poured too much. When asked to pour a standard size beer into a 32-ounce cup, some students filled the cup to the top! For these students, each of their drinks actually equaled 2.5 standard drinks."
Furthermore, in all three pouring tasks, the magnitude of the discrepancy increased with cup size.
"These findings suggest that students drink more than they think," said White, "which means that survey data probably underestimate actual drinking levels on college campuses. This is obviously not good news, neither for those of us who use surveys in our research, nor for those of us trying to deal with alcohol misuse on college campuses. The scale of the problem could be bigger than we thought."
"The fact that many students probably consume more alcohol than their survey responses suggest could help explain some of our previous findings about the consequences of drinking," added Courtney Kraus, second author for the study. "We've observed that a surprisingly high percentage of college students experience alcohol-induced memory blackouts, more than might be expected based on their self-reported consumption. The high incidence of blackouts makes more sense if students are actually drinking more than they think."
Furthermore, added Ralph Hingson, professor of social and behavioral sciences and Associate Dean for Research at the Boston University School of Public Health, the consequences of college drinking extend far beyond campus perimeters. "A lot of the people who are being affected are not just the drinkers, they're people affected by the behavior of the drinkers," he said. "Probably about half of the traffic deaths that are college-drinking related are pe