Lifetime abstainers from alcohol were 0.8% of the sample. In Cohort II, non-abstainers were asked, “How old were you the first time you had more than just a sip of beer, wine or spirits?” Cohort III was asked, “How old were you the first time you had a full drink of beer, wine or spirits?” Responses ranged from 1 to 35 years. To reduce the influence of low values, individuals reporting ages below 5 years were equated to 5 years. The variable was minimally skewed and moderately kurtotic (skewness=−0.34, kurtosis=5.00). Transformation of the variable was ineffective in reducing kurtosis; therefore, the raw variable was used and an estimator robust to deviations from normality was employed in all analyses (see Statistical Analysis). Reported ages of drinking initiation were 15.9 years in Cohort II and 15.9 years in Cohort III. In the combined sample, mean ages of drinking initiation for men and women were 15.4 years (SD=2.5) and 16.2 years (SD=2.5), respectively. These data demonstrated excellent retest reliability in recall (r(161)=.82, p<.0001) and age-related bias was minimal (r=.03). The age of alcohol initiation was minimally associated with year of birth (r=−.01) and year of assessment (r=.01).
