Why are some people more prone to alcoholism than others?

Many factors: Genetics plays a major rôle. If a person's family members were alcoholics, he/she may have inherited the gene(s) that may predispose him/her to alcoholism at some point in his life. However, social environment the person lives in plays a very important rôle as well. Peer pressure, social influence and personality traits may all predispose that person to develop alcohol dependence/addiction.

Genetic factors: There is some "genetic predisposition" on children of alcoholics. This may be related to the chemistry of the brain and the centers for pleasure. Also children learn from the behavior of people who surround them.