<Table> <Tr> <Td> </Td> <Td> This article is an orphan, as no other articles link to it . Please introduce links to this page from related articles; try the Find link tool for suggestions . (April 2017) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article is an orphan, as no other articles link to it . Please introduce links to this page from related articles; try the Find link tool for suggestions . (April 2017) </Td> </Tr> <P> Charles Spearman developed his two - factor theory of intelligence using factor analysis . His research not only led him to develop the concept of the g factor of general intelligence, but also the s factor of specific intellectual abilities . L.L. Thurstone, Howard Gardner, and Robert Sternberg also researched the structure of intelligence, and in analyzing their data, concluded that a single underlying factor was influencing the general intelligence of individuals . However, Spearman was criticized in 1916 by Godfrey Thomson, who claimed that the evidence was not as crucial as it seemed . Modern research is still expanding this theory by investigating Spearman's law of diminishing returns, and adding connected concepts to the research . </P> <P> In 1904, Charles Spearman had developed a statistical procedure called factor analysis . In factor analysis, related variables are tested for correlation to each other, then the correlation of the related items are evaluated to find clusters or groups of the variables . Spearman tested how well people performed on various tasks relating to intelligence . Such tasks include: distinguishing pitch, perceiving weight and colors, directions, and mathematics . When analyzing the data he collected, Spearman noted that those that did well in one area also scored higher in other areas . With this data, Spearman concluded that there must be one central factor that influences our cognitive abilities . Spearman termed this general intelligence g . </P>

Who opposed the two factor theory of intelligence