On Hebb's criticism of Jensen.

Notes that D. O. Hebb's (see record 1990-56823-001) criticism of A. R. Jensen's (1969) consideration of the contributions of environment vs heredity to IQ is based on a failure to distinguish between the variance within a particular group and the variance between groups. Use of a one-group analysis cannot show the effects or importance of a factor in determining an aspect of behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)