The nature versus nurture debate has been raging for decades and continues to rage today. However, we now have a great deal of insight into intelligence and what factors contribute to it. In fact, psychologists attribute both nature (genetics) and nurture (environment) to the level of intelligence that individuals have.
On the genetics side, a great deal of adoptive study has provided evidence of a degree of genetic influence to our intelligence. Using studies that involved twins separated at birth, and those separated and adopted, psychologists were able to eliminate many of the confounds that had previously caused other studies to fall apart. These studies found that adopted children tended to have more in common as far as IQ with their biological mother instead of their adoptive parent. Now at this point you might think that this is fairly obvious. However, think about the nurture side of the argument. This study showed that genes do in fact weigh on intelligence and it is not simply the influence of environment that shapes our intellect.
Unfortunately, as of yet researchers have been unable to identify exactly which genes are involved in intelligence. However, this doesn’t mean that they aren’t there and it may take time to single these genes or gene. We can also look to the brain for correlation to our intelligence. Although our intelligence has only a slight correlation to our brain size, it does have a little impact. What is also notable is that certain areas of the brain also influence intelligence. Some parts of the brain correlating to specific intelligence areas, such as spatial intelligence or mathematical intelligence, have been shown to play a part in intelligence. In Albert Einstein a specific part of his brain relating to spatial intelligence was found to be larger and this is attributed to higher intelligence in this area (Canadian Press, 2005).
The nurture side of the debate deals with the impact of environment on our intelligence. In fact, it is noted that each school year a child gains 3.5 IQ points. This demonstrates the importance of school on intelligence. Additionally, child psychologists and doctors emphasize talking to the child at an early age and interacting with so as to develop their ability for speech and more complex thought. It is interesting and unfortunate to note the impact of mental abuse to developing children. Children who spend their times sitting in a room with toys and no human interaction are often slower to develop and/or develop larger mental deficiencies. This alone is a good testament toward the impact of nurture or environment on intelligence and the development of intelligence.
In the adoptive studies shown earlier Romero and Kemp note that the study patients still show a connection in cultural norms. They likely attend the same sorts of schools and social experiences, which taints the wholly genetic factor to intelligence (Romero, Kemp, 2007). Where one grows up, where they attend school, how many days they go to school, what their family life is like, all these things contribute to intelligence.
While the nature-nurture debate won’t be solved tomorrow or probably even the day after, the Human Genome Project, as well as the adoptive twin studies have set a firm basis for further study and further answers. At this point our only conclusion can be that both nature and nurture are responsible for our intelligence. Both nature and nurture contribute to how and what we learn, what we retain, what we are exposed to, and what we ultimately end up specializing in.
References:
Canadian Press, (2005 Dec 23). Study Links Brain Size, Intelligence. Retrieved May 31, 2007, from CTV Globe Media Web site: http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20051223/brainsize_intelligence_20051223/20051223?hub=SciTech
Myers, D. Psychology 8th Edition. Worth Publishers.
Romero, A, & Kemp, S (2007). PsychologyDemystified.New York City: McGraw Hill.
