The study found later in life, there was a strong correlation between high IQ in young adulthood and preference for wine over beer. This is regardless of their socioeconomic status.
22% of men who were grouped into the highest of five IQ categories at age 18 tend to prefer wine in their 30s, compared to 9% of the men grouped in the lowest IQ category.
In their 40s, the differences were even more: 39% of the men with the highest IQs, but only 13% of those with the lowest, preferred wine.
According to the study, “in the predominantly beer-drinking Danish population…wine drinking has traditionally been a sign of high social standing.”
This means the correlation among education, social status, income, and intelligence could explain their findings.