Scores on a mental development scale were correlated for 8-month-old twins and other sibling pairs. Greater correlations were found between twins than sibling pairs. (ST)

Investigates the ability of 2-year-old children to pretend that one thing is another. Results indicate that when one thing is substituted for another, pretending varies as a function of the number of substitutions. (LLK)

Investigated the possibility that evidence of frequency discrimination might be found when the experimental procedures involved the conjugate reinforcement of nonnutritive sucking. (SDH)

This study was designed to assess the acquisition of conservation of number on equal addition tasks through scalogram analysis to determine if this analysis defines a scale or continuum. Ten block tasks administered to 85 kindergarten children validated Piaget's theory that cognitive development is sequential and continuous. (Author/ED)

Attempts to refute Riegel's (1973) claim that Piaget's formal operations distort reality for the sake of logic. It is suggested that Piaget's figurative-operative distinction is dialectical and that Piaget's theory is valuable precisely for its resolution of how a person remains internally ordered while adapting to the external world. (JMB)

Paper presented at the Merrill-Palmer Institute on Research and Training of Infant Development (Detroit, Mich., Feb. 15-17, 1968).

Paper presented at the Merrill-Palmer Institute on Research and Training of Infant Development (Detroit, Mich., Feb. 15-17, 1968).

To compare various cognitive treatment approaches for ameliorating difficulties of hyperactive children on tasks requiring sustained vigilance and accuracy, 48 hyperactive boys (mean age 9 years 4 months) were randomly assigned to one of four training conditions: inhibitory control training, attention training, combined training, or control. The…

The interest in developmental sequences and learning hierarchies is growing. One approach to the study of such sequences is to gather data on several variables, each of which corresponds to a stage, step, or phase in the sequence and to examine the associations between the variables as displayed in a contingency table. If the variables are…

Children's acquisition of developmental milestones is examined within the framework of a developmental-interactive system. Piaget's stages of cognitive development are reviewed and developmental aspects of language acquisition including inner language and expressive language are discussed. (JMB)

THIS STUDY DEALT WITH THE CONCEPT OF DEDUCTIVE LOGIC AND ITS USE BY ADOLESCENTS, AGES 10-18. TWO EMPIRICAL QUESTIONS OF CONCERN IN THIS STUDY WERE (1) THAT OF READINESS FOR MASTERY OF LOGIC AND (2) THAT OF THE NATURAL-CULTURAL DEVELOPMENT OF MASTERY OF LOGIC. TWO DEDUCTION TESTS WERE DEVELOPED, ONE FOR EACH OF THE TYPES OF LOGIC TREATED. THEY WERE…

This study investigated the ability of the Neonatal Behavioral Assessment Scale (NBAS), in combination with neonatal histories and developmental assessments, to predict mental and motor performance of 9-month-old infants on the Bayley Scales of Infant Development (BSID). Fourteen normal, full-term infants and 10 average-for-gestational-age,…

This study provides evidence of sex-typed behavior in the spontaneous play of infants between 9 1/2 and 15 1/2 months. Eight boys and eight girls at 9 1/2, 11 1/2, 13 1/2, and 15 1/2 months were observed during 15 minutes of free play with a variety of realistic toys equally divided into male, female, and neutral categories. Stereotypical,…