Charles Spearman (1904) set out to estimate the intelligence of 24 children in his village school. He discovered a relationship between each child's performance in a number of domains (including teachers' ratings of 'cleverness' and ratings by other students of their 'common sense out of school') and measures of their ability to discriminate light, weight and pitch. In other studies, he found strong associations between scores on examinations in different subject areas such as classics and maths. Linking together these strands of evidence, Spearman concluded which one of the following statements to be true? * The height of the child and the light in the room affected their ability to learn and hence their IQ. Intelligence must be a general facility, like a mental energy that is applied to all tasks. Teachers were poor judges of their students' abilities. Trving to measure intelligence in children was an impossible task