Digit ratio, nicotine and alcohol intake and national rates of smoking and alcohol consumption

The intake of nicotine (mainly through smoking) and alcohol has public health consequences. However, it is unclear whether all factors that affect individual and national rates of consumption are known. Prenatal testosterone (PT) may influence smoking and alcohol choices through effects on personality. Thus, morphological markers of PT may correlate with smoking and/or alcohol intake choices. Here we examine the relationship between individual values and national means of 2D:4D, a putative negative correlate of PT, and intake of nicotine and alcohol in a large sample of men and women, i.e. the BBC Internet Study. High intake of nicotine was related to high 2D:4D and high intake of alcohol with low 2D:4D. These findings were independent of sex, age, height, education, and individual choices regarding nicotine or alcohol intake. National means of 2D:4D were positively correlated with number of cigarettes consumed per nation after the removal of the effects of gross domestic product (GDP), average height and consumption of alcohol. Alcohol consumption correlated negatively with national 2D:4D after the influence of GDP, average height and consumption of cigarettes per nation were removed. We conclude that PT may have organising effects on smoking and alcohol intake choices.