The selected bibliography contains about 400 references taken from a keysort file of more than 45,000 references, compiled from commercially available data bases and published sources, relevant to gerontology. Those of questionable accuracy were checked or deleted during the verification process. Most references are in English and were selected…

This paper reviews studies in which scores on Piagetian tests of logical thought were correlated with IQ, mental age (MA) and chronological age (CA), and examines the possible effects of the size of the age range and mean age of subjects on these correlations. The data included 44 groups of subjects obtained from 36 studies in which Piagetian and…