Choose your main subject. You can choose yourself, a friend, or a family member. The relatives you compare your main subject with can be parents, a parent and a sibling, two siblings, or a parent and a grandparent. Many human traits are complex, because more than one gene controls them. As a result, there are a variety of possible traits. For example, there are several possible eye or hair colors among humans. Even with this complexity and variance, there are traits that tend to show a dominant or a recessive inheritance pattern. This table shows some common dominant and recessive traits in humans and gives the genetic abbreviation for each trait.