IQ Ratings: Nature or Nurture?

Nature vs. Nurture: The Debate on Intelligence

Numerous scholars have debated whether intelligence is genetic or environmental. Adoption studies, twin studies, and family studies are all based on intelligence, which is described as a person’s ability to reason, organize, and solve problems, think abstractly, and comprehend complex ideas.

The Role of Genetics in Intelligence

Both, to differing degrees, are thought to play an important role in the growth of a person’s intelligent mind. The limits of an individual’s intellectual potential are said to be determined by genetic components. The world nurtures a person and allows them to understand their intellectual potential. In the professional world, psychologists take a nature view of IQ. In their viewpoint, an individual is born with the intellectual capacity that enables them to understand their environment. According to this aspect, intellectual capacity gradually increases throughout childhood, and that learning only plays a limited role in the development of a person’s intellectual mind.

The Role of Environment in Intelligence

Empiricists, on the other hand, argue that children are not born with a predetermined level of intellect leaving room for a lot of improvement through learning processes. According to this view, intelligence is a product of learning to mean that environment plays a crucial role in the development of a child’s brain capacity.

Research into the role of Nature vs. Nurture in the Determination of a Person’s IQ

Role of nature and nature in the development of intelligence has been studied for a while now, and it has been concluded that both are equally important. An individual’s environment of upbringing dramatically affects their cognitive abilities in early childhood and throughout most of their teenage years. The genetic component of an individual is more prominent as a person grows old when it can account for more than 60% of IQ variance (Chamorro, Tomas et al. 753).

Inspection time, which is the least amount of time an individual, takes to recognize a known stimulus accounts for 20 percent of IQ variance. Behavioral Genetics (2001), finds that the relationships between perceptual speed (minimum inspection time) and verbal IQ and between perceptual speed and performance IQ are due to a shared genetic factor that accounts for 10% in verbal IQ variance and 22% of performance IQ variance (Posthuma, D. et al. 601).It shows that perceptual speed is a determined by a standard genetic factor.

In another research by Psychological Science, Self Perception Abilities (SPA) is found to account for 51 percent of genetic heritability while environment accounts for only 2 percent of SPA variance (Chamorro, Tomas, et al.). It is in sharp contrast with the belief that SPAs are environmentally driven. The article postulates the discovery of ’’SPA genes’’ in the future due to the high correlation between SPA and intelligence.

Despite the overwhelming influence of genetic factors on IQ, some research propositions have proven or attempted to prove the influence of nurture environment on the development of a person’s cognitive ability.

The Proceedings of the National Academy of Sciences (PNAS) research on the subject concludes that cognitive ability is environmentally malleable and the variance is high when the environment disparity is high (Kendler, Kenneth S. et al.). Another research by the organization finds that there are differences in IQ between breastfed children and those that are not breastfed. The study shows that the difference between the IQ of well-breastfed children and those that are not breastfed to be between 5.6 and 6.3 IQ points (Caspi, A. et al.).

Conclusion

Research on environmental effect on intelligence is correct for showing the impact of nurture level on a child’s mental development. However, inherited genes account for an individual’s cognitive prowess, and without it, the environment is of little significance.

The natural disposition of an individual’s genetic makeup is an essential factor in determining their IQ and the environment though essential plays second fiddle when assessing intellectual capacity.

Works Cited

Caspi, A. et al. “Moderation Of Breastfeeding Effects On The IQ By Genetic Variation In Fatty Acid Metabolism.” Proceedings Of The National Academy Of Sciences, vol 104, no. 47, 2007, pp. 18860-18865. Proceedings Of The National Academy Of Sciences.

Chamorro-Premuzic, Tomas et al. “More Thanmore Just IQ: School Achievement Is Predicted By Self-Perceived Abilities_x0097_But For Genetic Rather Than Environmental Reasons.” Psychological Science, vol 20, no. 6, 2009, pp. 753-760. Elsevier BV.

Kendler, Kenneth S. et al. “Family Environment And The Malleability Of Cognitive Ability: A Swedish National Home-Reared And Adopted-Away Cosibling Control Study.” Proceedings Of The National Academy Of Sciences, vol 112, no. 15, 2015, pp. 4612-4617. Proceedings Of The National Academy Of Sciences.

Posthuma, D. et al. “Perceptual Speed And IQ Are Associated Through Common Genetic Factors.” Behavioral Genetics, vol 31, no. 6, 2001, pp. 593-601. Elsevier BV.