In this article, the authors aim to make accessible the careful application of a method called instrumental variables (IV). Under the right analytic conditions, IV is one promising strategy for answering questions about the causal nature of associations and, in so doing, can advance developmental theory. The authors build on prior work combining…

Tested infants' understandings of self and mother in the domains of agency and featural knowledge. Four developmentally sequential tasks were administered to infants. It was hypothesized that infants would pass the mother versions of feature tasks before the self versions, and would pass the self versions of agency tasks before the mother…

Investigated whether and how children age 5 to 7 employed counting to measure and integrate the duration of two events, which were accompanied by metronome beats for half the children. The rhythm enhanced use of counting in younger children. By age 7, most counted spontaneously, using sensible counting strategies. (SKC)

Studies young children's behavior regarding acceptability of objects (cookie, comb and juice) that were contaminated with insects or human hair. (NH)

Kim (1985) found that both English-speaking and Korean-speaking children find true negative sentences more difficult to verify than false negative sentences. A closer examination of the findings reveals that the difficulty is greater among Korean-speaking children. (Author/RH)

Replies to Akiyama's critique, pointing out areas of agreement between the Kim and Akiyama studies and areas of disagreement. Concludes that, contrary to Akiyama's argument, the Kim (1985) data would not directly challenge the cognition primacy hypothesis in any serious manner. (RH)

Examined the development of pattern recognition in infant pigtailed macaques using the familiarization novelty technique. Results indicate that by at least 200 days postconception subjects show a consistently reliable visual response to novelty. (Author/RH)

This study documented a developmental model of children's understanding of the simultaneity of two emotions. Fourteen children at each of the nine age levels from 4 to 12 were studied. Children were questioned about (1) two emotions of same valence directed at the same target, (2) same valence/different target, (3) different valence/different…

Involving children three and four years of age, studies examined the basis for the difficulty of discriminating between left-right orientations of a shape in standard two-choice task. It was concluded that difficulty of left-right judgments lies in the cognitive demands of the task and is to be understood in the same terms as other problems in…

Tested the hypothesis that preschool children between 2 1/2 and 6 1/2 years of age would progress though a stepwise sequence of developing ever-clearer boundaries between fantasy and reality. Findings supported the validity of the hypothesized sequence. (RH)

Spatial matching--the ability to distribute search effort in accord with the distribution of hidden resources--was studied in 18- to 54-month-old children. The principal development was the appropriate use of win-shift response. (Author/RWB)

Tested the hypothesis that understanding of the pretend-real distinction develops earlier than understanding of the theoretically related apparent-real distinction. Found 3-year-old children consistently performed better on pretend-real tasks than on apparent-real tasks, even when the tasks were identical except for the distinction tested. (SKC)

Demonstrates young children's shift toward a taxonomic basis for organization of both named and depicted objects. Concludes that perceptual organization in young children cannot be attributed to an inability to ignore visual information but seems to be based upon the centrality of perceptual features to the representation of objects. (Author/NH)

Three experiments test object permanenece in 3 1/2- and 4 1/2-month-old infants, and use an impossible-possible-habituation event format. The 4 1/2-month-olds, and the 3 1/2-month-olds who were fast habituators, look reliably longer at the impossible than at the possible event. Results seriously question Piaget's (1954) claims regarding the age at…

Reply by Jerome Kagan to a recent article by Block, Gjerde, and Block (1986) which questions the validity of the construct of reflection-impulsivity. Kagan alleges flaws in the logic of the authors' (Block, Gjerde, Block) position and in the inferences drawn from their data. (Author/RWB)