Intelligence can be defined as the ability to acquire knowledge and skills. There are several theories that attempt to describe intelligence, including general intelligence, two-factor theory, multiple intelligences theory, and triarchic theory. Intelligence is measured using IQ tests, which compare a person's score to others of the same age. Both genetics and environment influence intelligence. While high IQ may predict some academic success, other factors like personality and motivation also impact life success. Problem solving involves both convergent and divergent thinking.