The data presented here must be viewed with several caveats in mind. First, we report detailed information gathered prospectively every five years from 453 families by the same principal investigators using the same interviews and questionnaires across two generations. Those steps allowed a unique opportunity to ask questions and compare results across time and across generations. However, it would be difficult and costly to carry out a similar approach in a much larger and more diverse population, with the result that it is unclear whether the current findings would be seen in families with different racial or ethnic backgrounds, a wider range of socioeconomic characteristics, and individuals from different areas of the world. Second, denial is a broad concept lacking general agreement regarding the optimal definition, and the current analyses focus on only one of several types of denial that relate to substance use and problems. Third, the global question of how individuals view their drinking pattern was developed for this study and has not been formally evaluated for reliability and validity. Finally, to keep the time spent by participants
