ABSTRACT
Some made a distinction between success at urban or business survival, the acquisition of 'street smarts', and the ability to solve abstract problems. Psychologists have not yet found more sensitive measures of our general mental abilities than our scores on sets of apparently quite trivial problems that they describe as 'intelligence tests'. The first intelligence tests were Alfred Binet's best attempts to predict how well young children were likely to cope with the nineteenth-century French school system. As we followed individuals over periods of 10 to 20 years, it became clear that some individuals' intelligence test scores remained almost constant while for others, particularly those with pathologies such as cardiovascular problems or diabetes. Until brain scanning became cheap and easy, there were few data to relate intelligence test scores to neurophysiology. Because we have no more sensitive tools than intelligence test scores to detect changes in mental ability.
