Social theories are what guides sociologists in their prediction of human behavior.  There are three main theories used in sociology, and they are symbolic interactionism, functionalism,. and conflict theory. Functionalism is how things work together in a society, how tradition, norms, and deviance are effected by different groups. To explain functionalism i will use the example: the effect religion has on underage drinkers. This social issue causes many young deaths by drunk driving, alcohol poisoning, and acts of violence.

         Functionalism looks at the relationship between things in a society, how they fit together. Almost all religions teach against drinking and other harmful subjects, but what percentage of teens actually listen? How many deviate? It also depends on how they are introduced to alcohol. Wether its friends, family, or even a stranger, it can effect their view on alcohol. They would struggle with their belief, and wether or not they trust the one giving it to them. A good example of a sneaky (and funny) introduction to alcohol:

              In David B. Larson and William P. Wilson's "Religious Life of Alcoholics" they found that 9 out of 10 alcoholics lost interest in church in their teenage years. Therefore teens that lose interest in religion and turn to drinking are much more likely to become an alcoholic. However in the same study, they found that you are much less likely to try alcohol, or try it once and turn your back on it. Some religions, however, require their members to drink, most of the time only a small amount of wine. These religious teenagers have more experience with alcohol due to this and handle it much better than those who religion teaches against the use of alcohol. Teenagers who have experience with alcohol are less likely to drive home drunk. Teenagers who aren't used to the effect of alcohol are more likely to drive home drunk. 60% of all fatal teenage accidents are because of alcohol. Teenagers with drinking parents are much more comfortable to call for a ride than those of a religious family, fearing the consequences if they are caught.
           
             What would make teens turn away from their religion, tradition, and towards alcohol? How big of an effect does religion really have on teen drinking?
                                                                                                                                                                        
References
David B. Larson and William P. Wilson: "Religious Life of Alcoholics," Southern Medical Journal, Vol. 73 (1980), pp. 723-727.
Patrick F. Fagan, Why Religion Matters: The Impact of Religious Practice on Social Stability, January 25, 1996, web.