However, if MZ twins share 100% of their genes, then they should both have 100% chance of developing depression, but according to this research, that is not the case; this research may also suggest that genetics are not the main factor in developing depression. Due to this, some psychologists believe that the theory of genetics cannot be used to explain depression. McGuffin et al (1996) conducted research on concordance rates using 177 identical and fraternal twins. They found that the concordance rate was 46% for identical twins, but only 20% for fraternal twins; these findings are significant as the concordance rate for identical twins is over double of that for fraternal twins. These findings support the biological explanation as it suggests that depression has a genetic factor.
The use of twin studies helps explain how there could be genetic factors in aggressive behavior. There are two types of Twin, monozygotic (identical) and Dizygotic (non-identical). If both types are studied in terms of aggression and the M-Z twins are more similar in aggressive behaviour it would suggest there is a genetic influence on aggression. Coccaro et al found that when comparing MZ and DZ twins, over 50 % of variance in aggressive behaviours between MZ twins could be attributed to genetic factors. Additionally the use of adoption studies can contribute to our understanding of genetic factors in aggression.
These findings support the biological explanation as it suggests that depression has a genetic factor. However, as all the pairs twins which were used in the study were raised in the same environment, the depression may have been learned or copied from another family member; therefore, this piece of research cannot be seen as valid. Also, this study could be said to lack reliability as it used a small sample size. Furthermore McGuffin et al’s research could be seen as reductionists as they are over simplifying the complexities of depression. In addition to this, some psychologists also argue that the genetic explanation to depression is deterministic as it claims that if an individual’s family members have depression, then they are definitely going to have depression.
‘Whereas MZ twins are identical in hereditary endowment, DZ twins are no more alike genetically than common siblings’ (Dolgard and Kringlen, 1976, p.213). The rationale is that if each member of a twin pair has a roughly identical environment, any difference in the average similarity of MZ or DZ twins must be due to genetic influence. Specifically, if there is a genetic contribution to the characteristic being studied (criminal activity), MZ would be expected to be more similar than DZ twins. The conventional way of expressing the degree of similarity between twin pairs is by using concordance rates. Dolgard and Kringlen (1976) cite Lange (1929) who studied 30 pairs of male twins and observed that 10 of 13 MZ were concordant, whereas only 2 of 17 DZ displayed concordance.
However our environment is dynamic and shaped by our own interactions with others. It is likely that the social environment for pairs of MZ twins is more similar than it is for DZ twins. Similarly it is unsurprising that phobia ‘runs’ in families, clearly families provide the ideal environment for ‘vicarious’ learning.Explaning these patterns with reference to genetic and other biological factors is arguably unnecessary. One weakness of the genetic argument is that the participants in the
Minimize the risks to subjects. Give subjects the right to withdraw from the research without penalty. | 6. Which results would not support the idea that genes play a significant role in behavior? (Points : 1) finding dizygotic twins to be more similar than monozygotic twins finding children to be more similar to their biological parents than to their adoptive
The first explanation of phobias is the genetic explanation, which argues that phobias are hereditary. Most if the family studies conducted by researchers have found that relatives of those with phobias are more likely to suffer phobias themselves compared with relatives of non-phobic controls. A twin study by Slater and Shields 1969 found 41% concordance in 17MZ twin pairs versus 4% in 28 DZ twin pairs for any type of anxiety disorder. However even though studies have proven to support the genetic problems there are a number of difficulties with family studies. The main problem is that in most cases family members share the same environment so it can be argued that it was the environment that caused them to equally learn the behaviour instead of the genetic relationship.
I think that we should learn more about them, understand the problems they face and learn what can be done to integrate them into the society, as they too have the right to lead a normal life. Brief Information Autism is a kind of Autism Spectrum Disorders, which includes a wide variety of behaviors and characteristics. 1 A person who is diagnosed with ASD can be a really smart person and a “slower” person. For example, people with Asperger’s Syndrom(variant of ASD) will have a higher intelligence compared to normal people, but not all autistics are that lucky. They will have problem in communicating with the others, for example, not able to look into people’s eyes while talking to them, and strange habits that are not explainable when they are young.
The Biological Approach to Abnormality The biological approach to abnormality mainly looks at the human body and uses it to explain why certain people show abnormal behaviours or disorders. Psychologists believe that genetics may be the cause of abnormality but in order to test this they must look at twins, they study monozygotic and dizygotic twins and look at the concordance rate to see if both twins have the same disorder. They use twins to look at genetics because they share mostly the same genes meaning in theory if an abnormality is due to genes then both twins will show signs of the abnormality. The second part of the body psychologists look at is the brain, by performing brain scans on people who do not show abnormalities and people who do show abnormality they can see if there is a physical difference in brain structure that could be cause of the disorder. For example people with schizophrenia are believed to have this disorder because they have a bigger gaps in their brains due to the shrinkage of brain tissue.
When studying the development of two individuals, it is feasible to assume that genetics play a more substantial role in their development than experience, if the subjects are chosen for their genetic similarities. However, when the subjects are unrelated, the contributions of genetics cannot be considered. Consider the deadly facts uncovered by Erin Brockovich in the film of the same name; some people became violently ill and died due to environmental factors, but not every member of the family suffered similar demise, despite living under the same