In this case, there are identical genetic aspects, yet the sociological aspects are different. By identifying which characters that these twins have are similar, and which are different, researcher were able to know characters that are due to inheritance and characters that are due to the environment. Consequently, they were able to identify that major depression is 31-42% due to inheritance, with similar results for anxiety, while 50-70% is due to inheritance in schizophrenia and bipolar (Datta, 2010, P46). Like that, it is clear that both factors, the genetic and the environmental, are intertwined and both play parts in developing mental …show more content…
An example of this is the case study of ‘Little Albert’, who acquired rats’ phobia because of a process of classical conditioning, after he was exposed in five occasions, to a loud sound, every time he tries to touch a presented rat. Although, he had no rats fear previously (McLannahan, p107). It is believed that an environmental factor played a role in this case. Through a learning process of an unpleasant experience, which led to developing this phobia, and the treatment was to undo this learning using the extinguishing conditional response, which involves presenting the rat without the loud noise for several times until finally there will be no fear from the rat. For other phobias as spider phobia therapists use a similar understanding and a similar treatment which is a gradual exposure to the stimulus. On the other hand, it is believed that there is a genetic root to other sorts of phobias like the sneck phobia, because snecks presented a threat to human in the evolutionary process, and having this fear led to the survival of human (McLannahan, p108). In addition, studies on twins showed evidence of the genetic aetiology of some human phobias related to some animals (Kendler et al., 1992 cited in McLannahan,