Poor Correspondence Between Self-Report and Behavior: College Students\u27 Definitions and Free-Pours of Standard Alcohol Servings

College students have difficulty defining a standard drink of alcohol, calling into question the reliability and validity of aggregated college student drinking self-report surveys. The current study compared 192 college students self-reported definitions of standard portions of beer, wine, and hard liquor to their behavior (free-pours). Aggregated data suggest participants were fairly accurate at defining a standard drink of beer (M=10.8 oz, SD=3.8 oz), but not wine (M=7.7 oz, SD=6.4 oz) or liquor (M=2.6 oz, SD=2.3 oz). Aggregated free-pour data suggest participants were fairly accurate at pouring a standard serving of beer (M=10.7 oz, SD=2.5 oz), wine (M=4.9 oz, SD=1.4 oz), and liquor (M=1.27 oz, SD=0.52 oz). Correlations between individual standard drink definitions and corresponding free-pours of beer, wine, and liquor were low (r=.193, p\u3c01, r=.377, p\u3c.001, and r=.134, p=.13, respectively). When each individuals pour was plotted against his or her definition, there was virtually no correspondence between their definition and their free-pour for all three alcohol types (Figure 1). Aggregate results mirror data from group studies, but single-subject analyses highlight the potential low reliability and validity of self-reported drinking, often the only data used to inform intervention, prevention, and policy decisions. Recommendations and suggestions for future research are discussed