Relation to Drugs and Alcohol and the Genetic Factor of Addiction - Essay Example

The authors of this study intended to verify the influence of social factors on these earlier findings. For this purpose, the authors used data from the Swedish Twin Registry consisting of 778 male-male and female-female twin pairs born from 1890-1958, and reared together and apart. The authors found that in male twins the pattern of regular use of tobacco suggested the involvement of both genetic, as well as rearing-environmental factors. The biometric model used by the authors suggested a 61% of the influence of genetic factors and a 20% influence of rearing-environmental factors on the regular use of tobacco.

In the case of female twins initially, the results were difficult to distinguish. Dividing the results into birth cohorts provided greater clarity regarding the regular use of tobacco in these female twins. Prior to 1925 the regular use of tobacco was low in women and seemed to have a greater bearing on the environment. From the later cohort results it was found that the regular use of tobacco was similar in pattern to male use, and along with the rise in the regular use of tobacco, it was found that there was a rise in hereditary factors.

This was particularly seen in female twins born after 1940. In the opinion of the authors, the strength of the study revolves around the use of both male twins and female twins brought up together and reared apart. Such a sample provides the best means to evaluate the impact of genetic and environmental factors on individual behavior. From the findings, the study concluded that genetic factors have an important role to play in the regular use of tobacco. When a social restriction is high, as seen in the case of the female twins, the genetic influence is diminished in comparison to the environmental factors, but as the social restrictions reduce the influence of genetic factors becomes greater, with the reduction in environmental factors of influence.