False. IQ is not one of the best predictors of success and happiness in life.
Intelligent Quotient or IQ is a test that rates one's intelligence levels (visual, spatial, numerical, mechanical and verbal intelligence) through a written test. The average IQ score indicating average intelligence levels is from 90-115. IQ is not a reliable predictor of success and happiness in life, because intelligence does not necessarily equate success. For instance, a person might have high IQ, but might not have a good job or good interpersonal connections, due to which the person is neither happy nor successful.