Psychologists use different kinds of methods to study genetics. These methods include the pedigree analysis, Karyotping, planned experimental breeding, and the twin study methods. The pedigree analysis refers to the pictorial representation of the members of a family with symbols representing the members of the family and lines representing genetic relationships. The Karyotyping method however, detects the number of chromosomes as well as their different abnormality using pictorial representation of the chromosomes. The planned experimental breeding on the other hand uses plant experiment and analysis to pass through generations. The twin study studies the disconcordance and the concordance of the fraternal and identical twins.
Twin studies are usually used to provide more support or more rejection for biological influences on the form of life in different perspectives including intelligence, mental illness, and behavior. If during a study, the concordance rate is higher in a twin study as compared to a non-twin study, the results can therefore suggest that a biological link exists between the areas of research. It is therefore assumed that since the twins share the same genes, if one twin suffers from mental illness, definitely the other twin would have it too. Despite the research suggestions of the existence of a biological relationship in several areas, the concordance rates have never been 100%, environmental explanations have been used to accompany these biological phenomena (Joseph, p. 71). For instance, some diseases might run in the family, but this might not necessarily mean that these diseases are genetic. A family might share some of their genes. Nevertheless, they also share environmental factors such as lifestyle habits, exposure to environmental pollution based on living or working conditions, and other social factors such as unemployment. This therefore implies that if a child and a father both have a heart disease, it could imply that they share genes or environmental and lifestyle factors.
Most scientists use twin studies, which involve the comparison of identical and non-identical twins. The identical twins, also referred to as monozygotic twins, are usually twins formed from the same egg, thereby sharing 100% of their genes. Non identical twins on the other hand, also referred to as dizygotic twins, come from different eggs despite sharing the mother’s womb. These latter twins share only half of their genes. Twin studies use the idea that if there is an inherited component to a particular illness, it is most likely that identical twins will more likely develop this illness than their non-identical counterparts because of the shared genes will (Joseph, p. 71). Psychologists use twin studies specifically to find inherent components. These researchers use the bell curve to determine the distribution of the gene heritability. In this curve, the people at the middle of eth curve are at average risk and those at the tail are at a lower risk of particular diseases. Psychological tests provide that psychologically related illnesses or characteristics are either inherited along the family lines, or attributed to environmental features. Therefore, twin studies not only provide researchers with information about genetics, but they also provide revelations about the importance of the environment in determining diseases that go along family lines.
Work Cited:
Joseph, Jay. "Twin Studies In Psychiatry And Psychology: Science Or Pseudoscience?." Psychiatric Quarterly 73.1 (2002): 71. Academic Search Complete. Web. 2 Feb. 2014.
