TWO SERIES OF STUDIES WHOSE SUBJECTS WERE EITHER HOODED AND ALBINO RATS OR YOUNG CHILDREN INVESTIGATED THE INFLUENCE OF EARLY EXPERIENCES ON LATER BEHAVIOR. IN THE FIRST, BOTH SUBSPECIES OF RATS WERE EXPOSED TO EITHER ENRICHED OR RESTRICTED ENVIRONMENTS TO ASSESS THEIR PROBLEM-SOLVING ABILITIES UNDER VARIOUS LEARNING CONDITIONS. THE RESULTS…

An attempt at defining and describing those factors which most often jeopardize the validity of naturalistic behavioral data is presented. A number of investigations from many laboratories which demonstrate these methodological problems are reviewed. Next, suggestions, implementations, and testing of effectiveness of various solutions to these…

The role of verbalization in children's mental operations was studied by comparing the mental operations children used in spatial perspective tasks (indicating another's view) and rotation tasks (imagining an object's rotation and one's own subsequent view). Each of 96 children (equal numbers of boys and girls, kindergarten and second grade…