The newspaper articles led people to believe that a single gene is responsible for a certain personality trait, in the same way a single gene can be responsible for a physical characteristics or disease. However, one gene alone cannot cause people to become anxious or homosexual or thrill seeking. Instead, many genes work together, and they do direct the combination of chemicals in the body. These chemicals, such as dopamine and serotonin (which affect a person’s mood) have a significant influence on personality.