There are large international differences on measures of cognitive competence, whether measured by IQ tests or by tests designed to assess school-related achievement. To make international comparisons meaningful as indicators of some underlying, culture-independent ability, tests must be measuring the same thing, with equal difficulty, in all countries. Intelligence should be defined as thinking ability independent of culture, but numerous examples can be cited of cultural variability on cognitive tasks, even very basic perceptual processes involved in spatial cognition. Even if there is a causal relationship between cognitive competence and desirable societal outcomes, there may be nothing that can be done to promote these desirable outcomes unless cognitive competence is malleable. Evidence suggests that education does build cognitive competence, and education and cognitive competence promote better social outcomes. However, within the limited sphere of the cognitive tests discussed here, cognitive competence appears malleable, education fruitful, and beneficial to society.