Complex sentence: Charles Spearman (1863-1945) was an English psychologist best known for inventing factor analysis and Spearman's rank correlation coefficient and for seminal work on human intelligence, including the discovery of the "g" factor.
Split into simpler sentences: Charles Spearman (1863-1945) was an English psychologist. He also did seminal work on human intelligence, including the discovery of the "g" factor.