Not sure how solid are these news items but today Science Daily publishes two articles on how genes make you this or that.
One quite common genetic variant (30% in USA) makes you apparently a worse driver, and a worse learner in general. However it is very advantageous to overcome neurodegenerative diseases. It is probably one of these cases of dynamic equilibrium in which two alleles offer different adaptative advantages, each one at a different cost.
Another of these allele variants has been found to increase the like for alcohol and make people drink more, however it is independent on the gene that predisposes to alcoholism (alcohol-addiction). This does not change that drinking frequently is the leading cause of alcoholism, of course, just mentions genes that predispose to drinking and to alcohol-dependence as distinct.
I just wonder what adaptative advantage does the gene for alcoholism has, sincerely. There must be something or would have gone extinct.