Heredity positive vs negative side.

Explanation:

To some degree this determines your general level of health. You inherit physical traits such as the color of your hair and eyes, shape of your nose and ears, as well as your body type and size. You also inherit basic intellectual abilities as well as tendencies toward specific diseases.

According to researchers, a previously known gene variant can cause individuals to perceive emotional events -- especially negative ones -- more vividly than others. A new study by a University of British Columbia researcher finds that some people are genetically predisposed to see the world darkly.