Genome Entry #6: Chromosome 11 Personality

In this chapter, we learn that the gene D4DR is located on the short arm of the chromosome. D4DR codes for dopamine is a neurotransmitter that motivates us to have action. It is the recipe for dopamine receptor protein and it is switched on in cells of certain parts of the brain but not in others. Dean Hamer shows in a study that D4DR correlates with “novelty-seeking” behavior, but only accounts for four percent of such behavior. It is shown that in the book it shows that too little and the person lacks initiative and motivation. Too much and the person is easily bored and frequently seeks new adventures. A long D4DR gene implies a low responsiveness to dopamine in certain parts of the brain, whereas a short D4DR gene implies a high responsiveness. People with long D4DR genes have low responsiveness to dopamine, so they need to take a more adventurous approach to life to get the same dopamine buzz that short-gened people get from simple things. 36 percent of this gene is heritable, and the rest is environmental. There could be over 500 heritable genes to control behavior. Other factors including diet, like cholesterol intake could also affect one's personality.