Genetics and Environment
According to the theory, genes play a strong role in the development of alcoholism.
Twin studies, adoption studies, and artificial selection studies have shown that a person's genes can predispose them to developing alcoholism. Evidence from twin studies show that concordance rates for alcoholism are higher for monozygotic twins than dizygotic twins-- 76% for monozygotic twins and 61% for dizygotic twins. However, female twin studies demonstrate that females have much lower concordance rates than males. Reasons for gender differences may be due to environmental factors, such as negative public attitudes towards female drinkers. Twin studies suggest that males are more likely to have a genetic predisposition for alcoholism. However, this does not suggest that a male who does have a genetic predisposition will become an alcoholic. Sometimes the individual may never encounter an environmental trigger that leads to alcoholism.
Adoption studies also suggest a strong genetic tendency towards alcoholism. Studies on children separated from their biological parents demonstrates that sons of alcoholic biological fathers were more likely to become alcoholic, even though they have been separated and raised by non alcoholic parents. Female show similar results, but to a lesser degree.
In artificial selection studies, specific strains of rats were bred to prefer alcohol. These rats preferred drinking alcohol over other liquids, resulting in a tolerance for alcohol and exhibited a physical dependency on alcohol. Rats that were not bred for this preference did not have these traits (Lumeng, Murphy, McBride, & Li, 1995). Upon analyzing the brains of these two strains of rats,it was discovered that there were differences in chemical composition of certain areas of the brain. This study suggests that certain brain mechanisms are more genetically prone to alcoholism.
The convergent evidence from these studies present a strong case for the genetic basis of alcoholism.
Read more about this topic: Disease Theory Of Alcoholism
Famous quotes containing the word environment:
“If the Revolution has the right to destroy bridges and art monuments whenever necessary, it will stop still less from laying its hand on any tendency in art which, no matter how great its achievement in form, threatens to disintegrate the revolutionary environment or to arouse the internal forces of the Revolution, that is, the proletariat, the peasantry and the intelligentsia, to a hostile opposition to one another. Our standard is, clearly, political, imperative and intolerant.”
—Leon Trotsky (1879–1940)