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:
“People between twenty and forty are not sympathetic. The child has the capacity to do but it can’t know. It only knows when it is no longer able to do—after forty. Between twenty and forty the will of the child to do gets stronger, more dangerous, but it has not begun to learn to know yet. Since his capacity to do is forced into channels of evil through environment and pressures, man is strong before he is moral. The world’s anguish is caused by people between twenty and forty.”
—William Faulkner (1897–1962)