Charles Spearman was a British psychologist best known for his work in the field of intelligence. He introduced the concept of g, or general intelligence, which suggests that a single underlying factor influences performance across various cognitive tasks. Spearman developed statistical methods, including factor analysis, to identify this general intelligence and its relationship to specific abilities. In addition to his work on intelligence, Spearman contributed to the study of psychometrics, the science of measuring mental capacities and processes. His research laid the groundwork for future theories of intelligence and has influenced educational practices and psychological assessments.