Week 8: Behavioral Genetics and Public Policy

This was the final week of my behavioral genetics course, which was a summing up of the major themes we had learned, and a few examples of how behavioral genetics will intersect with public policy.  Here are the notes:

4 Laws of Behavioral Genetics:

1. All human behavioral traits are heritable.

• For many behavioral traits the strength of heritable influence increases with age.
• Impoverished environments can limit genetic influences on desirable traits, and protective environments can minimize genetic influences on undesirable traits.

2. The shared family environment has minimal impact on individual differences in behavior.

• It doesn't mean that family has no effect on a reared child, but that the family environment affects each child differently.  

3. The non-shared environment exerts a major influence on individual differences in behavior.

• What are the specific effects that matter?
• The "gloomy prospect" - ie, what makes me neurotic is different from what makes you neurotic.  

4. Human behavioral traits are polygenic.

• Effects of any one gene on personality, general cognitive ability, or most complex medical issues are small.  Likely, thousands of genes are contributing.

Genomic Medicine:  What will it take to use genes in medical treatment?
1.  Disease risk can be accurately forecast genetically, preferably prior to disease onset Genetic Prediction

• As it becomes cheaper, more and more people will have their genome sequenced, and we will learn more and more about the genetics of disease.

2.  Prevention/intervention efficacy will differ depending on each individual’s genotype Individualized Medicine (GxE)

• Pharmacogenomics - learning how your individual genes affect the efficacy and toxicity of a particular drug on you.  

3. Individuals will want to know their risk status and once known be willing to take preventive action Genetic Counseling/Behavioral Medicine

• What are the psychological consequences of a positive test result (especially for diseases where there is currently no treatment)?  
• Many individuals who are known to be at risk choose not to get tested.  

Genomics and the Law

• We tend to attribute less personal responsibility when phenotypes are highly heritable, and more personal responsibility when behaviors are not as attributable to genetics.
• Emphasis on choice - defendants don't choose to have genes with a greater vulnerability to aggressive or impulsive behavior, the same way that defendants don't choose to be abused as children.