Beyond Versus: The Struggle to Understand the Interaction of Nature and Nurture

8 Of Dogs, Daycare, and Discipline: A “Genetic Guide to Parenting”?

Consider the following three questions: • Should parents buy their child a dog or a cat? • Should parents send their infant to daycare? • Should parents, when their toddler has a temper tantrum, respond with empathy directed at the child’s frustration or with punishment directed at the child’s misbehavior? Answering these questions is complex. In contrast to childhood maltreatment (discussed in the last chapter), which everyone can agree is harmful, decisions about the family pet, childcare, and discipline are subjects of friendly debate and involve both personal and familial evaluations of finances, schedules, and parenting philosophies. Might genetic information about the child figure into such decisions? I believe it could, and in the near future. My goal in this chapter is to say why I think a “genetic guide to parenting” is a very real possibility and to then evaluate whether or not this would be a good thing. Incorporating genetic information into traditional parental decision making, I hope to show, will fundamentally alter what counts as a “treatment.” This alteration would have both advantages and disadvantages. On the one hand, it would empower parents by putting treatment, which was previously the exclusive purview of medical professionals, directly into the hands of parents. On the other hand, it would transform the way parents conceive of certain parental decisions, reshaping how parents think about the rationale for various childcare choices. Differential Susceptibilities Involving the Early Childhood Environment My reference just above to a genetic guide to parenting might cause the reader to think I’ve suddenly forgotten the lessons of the last seven 8 Of Dogs, Daycare, and Discipline: A “Genetic Guide to Parenting”? 188 Chapter 8 chapters about the interaction of nature and nurture and slipped into a perspective of genetic determinism. But that is not the case, for the scientific research I will discuss below involves cases of gene-environment interaction , wherein interaction effects have been reported between specific genes and specific environments. What makes these cases interesting and might make for a genetic guide to parenting comes from the fact that the environmental variables in the cases are actively shaped by parents when they make decisions about the exposures and experiences of their child’s early life. All of the cases involve interaction effects that are so extreme that the riskier genetic group in one environment becomes the least risky group in a different environment; the cases, that is, all involve interactions that change in rank, constituting differential susceptibilities to the traits in question.1 Allergies: Dogs, Daycare, and the CD14 Gene “Atopy” derives from the Greek word for being out of place. People with atopic syndrome are hypersensitive to common environmental antigens. This hypersensitivity leads to an overactive immune response, resulting in a range of allergic symptoms: atopic dermatitis (more commonly called “eczema”), allergic rhinitis (more commonly called “hay fever”), allergic conjunctivitis (more commonly called “red eyes”), allergic asthma, and food allergies. Hundreds of millions of people worldwide suffer from allergies. According to the United States’ National Institute of Allergy and Infectious Disease, 7 million children in the United States are asthmatic. 30% of the U.S. population (mostly children and adolescents) suffers from eczema. Respiratory allergies, such as hay fever, affect 10% of U.S. children. And 5% of children in the United States have food allergies. Many of these children with allergies will grow into adults with allergies. And as anyone with allergies can tell you, allergic symptoms can be seriously debilitating. Quality of life is diminished when people with allergies avoid certain environments that might trigger an allergic response. Serious episodes, such as asthma attacks, can even result in death. The financial toll is significant—every year, billions of dollars are either spent on medical care for allergies or lost due to missed work and school days.2 The story of allergy genetics over the last two decades is quite similar to the story of behavioral genetics over that same period. As told in chapter 4, initial discoveries of candidate genes associated with behavioral traits in the 1990s brought great excitement, but that excitement gave way to disappointment when many of the original candidate genes failed to replicate Of Dogs, Daycare, and Discipline 189 in new populations. In chapter 4, remember, Moffitt and Caspi sought to move past the direct gene-behavior link by incorporating environmental variables such as breastfeeding and drug use into their analysis. Scientists studying allergies and asthma made...