Five measures of intellectual level (IQ, MA, teachers' estimates of intelligence, level of object permanence, and representation of causality) were correlated with effectance variables and with each other for 42 quadraplegics (one to 12 years). Results reveal some relationship between intellectual level and effectance, although cognitive ability…

A study involving 18 individuals with pervasive developmental disorders (PDD) (ages 9-21) and 67 controls found total score on the Biber Cognitive Estimation Test for both individuals with PDD and controls progressed consistently with mental age, development being the most dramatic around the mental age of 8 years. (Contains references.)…