Summary

Intelligence is commonly viewed as the ability to learn from experience as well as to adapt to the surrounding environment. There are several approaches to understanding intelligence, including the psychometric, cognitive, biological, cultural/contextual, and systems approaches. Each approach places an emphasis on different psychological aspects of intelligence as well as on different ways of investigating it. The psychometric approach is largely based on statistical methods, especially factor analysis. The cognitive approach studies mental representations and processes. The biological approach is largely brain based. The cultural/contextual approach emphasizes the role of culture in defining what constitutes intelligence in a given cultural setting. And the systems approach looks at intelligence in terms of complex systemic interactions. Two systems theories are Howard Gardner’s theory of multiple intelligences and Robert Sternberg’s theory of successful intelligence. Gardner’s theory argues that there are eight distinctive intelligences, whereas Sternberg’s theory argues that intelligence comprises creative, analytical, practical, and even wisdom-based skills.

Intelligence appears to be at least somewhat malleable. A number of programs have had modest to moderate success in helping people to improve their intelligence. These programs work best if they are sustained. They work less well if used only for short periods of time. Schooling is one way of increasing intelligence.

The Flynn effect shows modifiability of intelligence across secular time. During the 20th century, IQs rose roughly 30 points worldwide, or 10 points per decade. These results suggest that environment can have a powerful effect, at least on IQ and over a generational time span. However, the increases experienced in the 20th century are not being experienced worldwide in the 21st century.