People differ in the speed which they learn things and how well and long they remember ideas. They also differ in the ability to understand ideas and how to use their knowledge in solving problems. A person’s intelligence depends on heredity and environment. Everyone is born with some kind of capacity that influences how intelligent he or she will be as an adult. What they do with this capacity is influenced by the person’ background. For example, if a person is beaten by his or her parents, he or she may become so upset that his or her intellectual talents remain underdeveloped.