Quote by Charles Spearman
"Those who refuse to measure refuse to know."
More from Charles Spearman
"Intelligence is not a single, unitary ability, but rather a general factor that influences performance across diverse cognitive tasks."
"The human mind possesses a general cognitive ability that affects success in all intellectual endeavors."
"Education should aim to develop the general factor of intelligence that underlies all mental abilities."
"Correlation analysis reveals the hidden structures of human thought and ability."