The present study had limitations. IV ethanol administration with clamping technique offers design advantages but introduces departures from external validity given that alcohol is typically consumed orally. Differences between IV administration and typical oral alcohol consumption may explain the magnitude of subjective response reported in this study, which was noticeably lower than in most oral administration studies involving comparable alcohol doses (e.g., Addicott et al. 2007; King et al. 2011). Young adults, who were primarily Caucasian and highly educated, comprised the sample, which limits generalizability of the results to other populations. In addition, the parent study was designed to make comparisons of subjective response to ethanol between family history positive and negative individuals. In order to draw clearer conclusions about differences by family history status with minimal confounding by effects of substantial alcohol exposure, the study recruited only non-alcohol-dependent social drinkers. Similarly, in the present study, differences across impulsivity levels are more likely to be attributable to implications of impulsivity rather than to effects of substantial alcohol exposure. While we believe this was a sound approach, it leaves unanswered the
