Critical Thinking Questions

1. A major focus of this chapter was the interaction of nature and nurture. Consider yourself and your family (regardless of whether you were raised by your biological parents). Identify some aspect of who you are that illustrates each of the five relations depicted in Figure 3.1 and answer these questions: (a) How and when was your sex determined? (b) What are some alleles you are certain or relatively confident you share with other members of your family? (c) What might be an example of a gene–environment interaction in your parents’ behavior toward you? (d) What would be an example of your active selection of your own environment that might have influenced your subsequent development? (e) What aspects of your own environment might have had epigenetic effects on your gene expression?
2. “Fifty percent of a person’s IQ is due to heredity and fifty percent to environment.” Discuss what is wrong with this statement, describing both what heritability estimates mean and what they do not mean.
3. Relate the developmental processes of synaptogenesis and synapse elimination to the concepts of experience-expectant and experience-dependent plasticity.
4. What aspects of brain development do researchers think may be related to the traits and behaviors of adolescents?
5. Think back over your activities and observations of the past day or so. What aspects of your environment may relate to the epidemic of obesity described in this chapter?
6. Consider Figure 3.13, which addresses malnutrition and cognitive development. Imagine an undernourished 6-year-old child living in the United States. Go through the figure and generate a specific example of something that might happen to this child at each point in the diagram. Now do the same for a 6-year-old living in a poor, war-torn country.