Intelligence theory can be roughly divided into several schools.

They are Spearman's two-factor theory and Thorndike's three-factor theory, thurston's group factor theory and guildford's three-dimensional structure model.

Intelligence refers to the ability of people to know and understand objective things and solve problems by using knowledge and experience, including memory, observation, imagination and ideological judgment. Howard gardner, a psychologist at Harvard University School of Education in the United States, put forward the famous theory of multiple intelligences, which changed the traditional concept of single intelligence, expanded the field of human thinking and understanding to a new world, and deepened the understanding of human beings.