Answer: D. Environmental factors play a more dominant role than genes do in shaping an individual’s behavioral traits.
Explanation:
The external environmental factors can be dominant over the gene expression. The factors such as drugs, temperature, chemicals, light, food and others can bring change in the behavior of the separated twins although they may have same genotypic and phenotypic traits. These factors can influence the working of the gene thus can influence the neural and muscular coordination, which may affect behavior. For example, alcohol and drugs can influence the gene expression and will affect the mental and muscular coordination, these may also influence the behavior the person may become aggressive or lethargic.
