An intelligence quotient or IQ is a score derived from a set of standardized tests of intelligence. Intelligence tests come in many forms, and some tests use a single type of item or question. Most tests yield both an overall score and individual subtest scores. Regardless of design, all IQ tests attempt to measure the same general intelligence. Component tests are generally designed and selected because they are found to be predictive of later intellectual development, such as educational achievement. IQ also correlates with job performance, socioeconomic advancement, and "social pathologies". Recent work has demonstrated links between IQ and health, longevity, and functional literacy.