Alcohol-related attitudes and drinking behaviour of 109 university students, all 20 years of age and older, were assessed at two time points: immediately before and three months after the drinking age in New Zealand was lowered from 20 to 18. Participants reported drinking smaller quantities of alcohol three months after, compared to immediately before, the new drinking age went into effect. Alcohol consumption was strongly predicted by attitudes toward the social aspects of drinking, but no attitude change over time was observed on any attitudinal dimension. In open-ended written comments a number of participants expressed negative feelings toward younger drinkers and commented that they were less likely to frequent places where younger drinkers would congregate.
In almost every country alcohol abuse creates difficult and dangerous social problems, many of which are linked to drinking by young adults. Although many governments have responded with legislative steps to restrict alcohol consumption in young people (e.g., Gonzalez, 1989; Lotterhos et al., 1988), New Zealand recently took the controversial step of lowering the drinking age from 20 to 18. Irrespective of other arguments for or against this legislation, there is little doubt that the reduced drinking age has correspondingly lowered the average age of the patrons of drinking establishments. Indeed, proponents of the legislation argued that one of its purposes was to bring underage drinkers into comparatively safe and controlled environments, such as bars and cafes, thereby regulating drinking behaviour and mitigating problems such as teenage binge-drinking (e.g., New Zealand Herald, 1999). Thus in December 1999, the social profile of drinking establishments changed literally overnight. What was the effect of an influx of younger, previously underaged drinkers on the attitudes and behaviours of others?
So framed, this is an inherently social psychological question, one that has never explicitly been studied. Indeed, relatively few studies have examined the effect of the decriminalisation of alcohol at all (new legislation typically increases restrictions on alcohol), and what research there is has understandably studied the individuals most directly affected. These studies suggest, often indirectly, that decriminalisation increases alcohol consumption and its associated problems in the affected population. Wagenaar (1982), for example, found a temporary increase in draft beer sales following a reduction in Michigan's drinking age from 21 to 18 in 1969 (although the researcher also found an increase when, in 1980, the age was raised again to 21). Cohen (1978) found increases in accident rates in U.S. states that had lowered their drinking ages, although in at least one case this effect was later attributed to changes over time in police reporting practices (Zylman, 1974). Smith and Burvill (1987) found increases in juvenile crime following a decrease of the drinking age to 18 in several Australian states. In New Zealand, the Alcohol Advisory Council (ALAC; 2002) has already attributed increases in traffic-related accidents and in unsafe sex to the decrease in the drinking age. Thus, the consequences of this legislation for those below the age of twenty may be quite significant.
Yet there is good reason to expect that the effects of New Zealand's new legislation will not be limited those under 20. In the context of university social life, whether one is of legal drinking age serves as a salient and relevant basis of social categorization. Therefore well-studied mechanisms of ingroup bias (Tajfel & Turner, 1979) are likely to operate when students over twenty years of age encounter younger students in a drinking environment. The results of such bias can be both attitudinal, in the form of stereotyping (e.g., Haslam, Turner, Oakes, McGarty, et al., 1992) and behavioural, in the form of ingroup favouritism (e.g., Turner, Brown, & Tajfel, 1979). …