vasqu060: October 2011 Archives
The nature-nurture debate is one of the oldest in the history of psychology. The basis of the debate is that either nature or nurture influences an individual's character traits. Proponents of nature state that we our born with genetic traits, or our traits have been carried from our parents to us, their offspring. Nurture proponents state that factors such as personal experiences and environment influence who we become. Although the nurture camp has been the most prominent, their ideas have come from John Locke theory of the tabula rasa or blank slate. According to Locke, humans are born with no innate characteristics, we take in that information as we observe our environment. Of course, we all know that both nature and nurture play a role in our characteristics, now it has adapted to which has the greater influence.
Like all other debates, this one has its own controversies. The controversial domains are: personality, intelligence, and mental illnesses. Scientists have used behavioral genetics to study the influence of nature and nurture in these psychological traits, it includes genes and environment. Genetic designs also allow scientists to estimate heritability of traits and diseases. Heritability is the extent to which genes contribute to differences in a trait among individuals. It is measured in the percentage of the veritability in a trait across individuals that is due to genes. If the heritability of a trait is 60 percent due to differences among individual's genes, then 40 percent is due to differences in one's environment. Some traits like height are highly heritable, between 70 to 80 percent in humans.
Experimental designs such as family studies, adoption studies, and twin studies as well, they track the presence or absence of a trait among different relatives to determine the contriutions of genes and environment of a trait. In family studies, researchers examine a particular trait among family members, particularly the ones raised in the same home. One drawback is that these studies do not permit us to isolate the effects of nature and nurture. Also,researchers use twin studies to examine the difference between identical and fraternal twins in character traits. From the basic logic of twins, we can infer if a characteristic is genetically influenced (assuming the environmental differences of this trait are the same), because identical twins are more alike in psychological traits.
Adoption studies test the extent to which children adopted to new omes resemble their adopted rather than biological parents. I myself hae observed this since I went to high school with a few adopted kids. They were adopted from Colombia and they acted like their adopted parents, They not only spoke English, but they also shared some personality traits with them as well. Selective placement is a practice utilized by adoption agencies, has caused a drawback in these studies. It is a drawback because investigators will incorrectly correlate the similarity between adopted children and their biological parents as a genetic effect. To improve this situation, they try to control for selective placement by correlating the biological and adoptive parents and their psychological characteristics.
Two weeks ago during discussion, we looked at the Bogul family which consisted of mostly criminals and whether nature or nurture influenced their offspring. Another such family with a common trait is the Gliadovskys. They cosist of Kirill and his wife Anna, who are both Russian-born trained concert pianists who have many awards and held performances internationally. They have a daughter, Anastassia, who also is well-trained (by her parents), and has won several awards herself. In some cases, her parents, being both excellent musicians, have shared that certain genetic trait with her. They also raised her in an environment which allowed her to achieve the similar level of success as her parents. With stories like these, the nature-nurture debate will go on indefinitely with more studies to show similar results.