Question

Heredity and Environment: What evidence indicates that environment and heredity contribute to intelligence? Which factor do you feel impacts intellectual development more, environment or heredity? Support your response.

Answer 1

Our behavior is a result of the interaction between hereditary and environmental factors. The biology of an individual provides the structure for a behavior, whereas, the environment provides the context that acts as a stimulant for the production of the behavior. Without the proper environmental conditions, a child cannot function fully according to his/her potentials. Every person owns a unique set of genes that separates them from other individuals. The kind of behavior a person would produce, however, depends on the environment one grows in. The cultural factors, social factors, supportive or unsupportive family environment, etc along with the genes work together in determining the intelligence of an individual. The interactionist approach, therefore, emphasizes that the difference between the individuals is due to the interaction between the genetic and environmental factors. Factors that are purely determined by genes include, eye and hair color, certain illness, etc. Genes determine the upper limit of how much an individual can attain, whereas, the environment determines the degree to which one can realize his/her potentials. In my opinion, I agree with the interactionist approach that emphasizes intelligence as a result of the interaction between the genes and the environmental factors. Whereas, family and twin studies show that intelligence is passed on by the families to their children and that there is a high correlation of IQ between the identical twins than the fraternal twins, it is still possible that even with high heritability a trait can be influenced by the contextual factors. Adoption studies show that adopted children have similar IQs to their adoptive parents, siblings who grew together have a more similar IQ than siblings who grew apart. Hence, both hereditary and environmental factors can be attributed to the difference in IQ between individuals.