more biological significance than the differences found between any human populations (e.g., the Spanish and Portuguese). Group differences The study of human intelligence is one of the most controversial topics in psychology, in part because of difficulty reaching agreement about the meaning of intelligence and objections to the assumption that intelligence can be meaningfully measured by IQ tests. Claims that there are innate differences in intelligence between racial and ethnic groups—which go back at least to the 19th century—have been criticized both for relying on specious assumptions and research methods and for serving as an ideological framework for discrimination and racism. In a 2012 study of tests of different components of intelligence, Hampshire et al. expressed disagreement with the view of Jensen and Rushton that genetic factors must play a role in IQ differences between races, stating that "it remains unclear, however, whether population differences in intelligence test scores are driven by heritable factors or by other correlated demographic variables such as socioeconomic status, education level, and motivation. More relevantly, it is questionable whether they [population differences in intelligence test scores] relate to a unitary intelligence factor, as opposed to a bias in testing paradigms toward particular components of a more complex intelligence construct." According to Jackson and Weidman, Test scores In the US, individuals identifying themselves as Asian generally tend to score higher on IQ tests than Caucasians, who tend to score higher than Hispanics, who tend to score higher than African Americans. Nevertheless, greater variation in IQ scores exists within each ethnic group than between them. A 2001 meta-analysis of the results of 6,246,729 participants tested for cognitive ability or aptitude found a difference in average scores between black people and white people of 1.1 standard deviations. Consistent results were found for college and university application tests such as the Scholastic Aptitude Test (N = 2.4 million) and Graduate Record Examination (N = 2.3 million), as well as for tests of job applicants in corporate settings (N = 0.5 million) and in the military (N = 0.4 million). In response to the controversial 1994 book The Bell Curve, the American Psychological Association (APA) formed a task-force of eleven experts, which issued a report "Intelligence: Knowns and Unknowns" in 1996. Regarding group differences, the report reaffirmed the consensus that differences within groups are much wider than differences between groups, and that claims of ethnic differences in intelligence should be