Drinking is normal; the WHO reports that 38.3% of the worlds population (or 2.7 billion people) over the age of 15 drank alcohol in the last year. Drinking is even more common in developed countries, 70.7% of Americans over the age of 18 (or 225 million people) drank in the past year.
Drinking is not new; Pottery fragments from China show traces of a fermented beverage preserved since 7000BC (McGovern et al 04). The ancient Greeks had a god dedicated to binge drinking
Drinking is also fattening, addictive, and lethal at high doses.
All of this begs the question what drives us to drink in the first place?
One model, developed by Cooper et al. divides drinking into 4 main motives that can all be more or less important to different individuals. The four factors are Social: drinking to

increase sociability, Coping: drinking to blunt negative emotions, Enhancement: drinking to increase positive affect, and Conformity: drinking out of a desire to conform or a fear of rejection. Research on these motives has shown that the outcomes of peoples drinking depend on the salience of each of these motives for specific individuals. For example, individuals who rate high on enhancement tend to drink the most. Interestingly individuals high in coping tend to experience certain neg-


ative consequences from their drinking such as lack of self-care more frequently than others, even when they drink less (Merrill, Wardell, and Read 2014).
These motives seem to have some biological basis as studies have found that some these motives are passed down from parents to their children. One study of Dutch families found that the effects of parental drinking motives on children depended in part on which parents had which motives. They found that stronger maternal coping were associated with stronger coping in younger adults (around 18 years old) and stronger social motives in older adults (around 20) while paternal enhancement motives were associated with stronger coping in younger adults and stronger overall drinking motives (Mares, Lichtwarck-Aschoff, and Engels 2013).
More specifically; research has shown that enhancement and coping motives are heritable in tobacco smokers but not in nonsmokers, implicating some kind of epigenetic effect.In order to refine this finding, Kristjansson et al. focusing on single nucleotide differences in two genes, one involved in serotonin (TPH2; rs138694) and one involved in dopamine synthesis (DDC rs3779084) investigated the precise nature of this effect in young adult female twins. In regular smokers, they found that the relationship between alcohol consumption and DDC

minor allele was mediated by coping and enhancement motives. This suggests that the DDC minor allele combined with the epigenetic and neurological changes associated with tobacco consumption made the enhancement of positive feelings, and the blunting of negative ones more desirable aspects of alcohol use (Kristjansson et al. 2012).
Drinking is a complex behavior that is caused by a variety of social and biological factors. As we refine our knowledge of the genetic, anatomical, and psychological effects and causes of drinking the picture is sure to become more complex. However, understanding how a persons genetic predispositions and behavioral choices affect their consumption of alcohol should be pursued in order to tailor interventions about alcohol abuse to individuals.
Kristjansson, S. D., Agrawal, A., Lessov‐Schlaggar, C. N., Madden, P. A., Lynne Cooper, M., Bucholz, K. K., … & Heath, A. C. (2012). The relationship between rs3779084 in the dopa decarboxylase (DDC) gene and alcohol consumption is mediated by drinking motives in regular smokers. Alcoholism: Clinical and Experimental Research, 36(1), 162-170.
Mares, S. H., Lichtwarck-Aschoff, A., & Engels, R. C. (2013). Intergenerational transmission of drinking motives and how they relate to young adults’ alcohol use. Alcohol and alcoholism, 48(4), 445-451.
McGovern, P. E., Zhang, J., Tang, J., Zhang, Z., Hall, G. R., Moreau, R. A., … & Cheng, G. (2004). Fermented beverages of pre-and proto-historic China.Proceedings of the National Academy of Sciences of the United States of America, 101(51), 17593-17598.
Merrill, J. E., Wardell, J. D., & Read, J. P. (2014). Drinking motives in the prospective prediction of unique alcohol-related consequences in college students. Journal of studies on alcohol and drugs, 75(1), 93.
http://www.who.int/substance_abuse/facts/alcohol/en/
http://www.niaaa.nih.gov/alcohol-health/overview-alcohol-consumption/alcohol-facts-and-statistics