A child can override inherited characteristics by specifying a new value for that characteristic. These overriding values do not affect the parent and are therefore considered local to the child. Local values can also be removed at any time, reverting the characteristic to its inherited state. The child has no choice in the value of his inherited attributes, only in local attributes.

For example, a child has inherited the attribute of blue eyes from his parent. If the child puts on a pair of green tinted contact lenses to hide his natural eye color, his natural eye color is overridden locally, and his eye color is green. When the tinted lenses are removed, the eye color reverts to blue, as inherited from the parent.