Final answer:
Handedness, or brain lateralization, refers to whether one is right-handed or left-handed. Approximately 90 percent of humans are right-handed and a growing number of experts believe that handedness is random.
Step-by-step explanation:
Handedness, or brain lateralization (i.e., whether one is right-handed or left-handed), is a cognitive development that can be inferred through evidence of the use of a dominant hand in creating and using tools. It is believed that about 90 percent of humans are right-handed. A growing number of experts believe that handedness is random and not determined by genetics.