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H M Wellman

Publications and source records attributed to H M Wellman.

31 records · Page 2Linked to original sources
PubMed1987

Infant search and object permanence: a meta-analysis of the A-not-B error.

Research on Piaget's stage 4 object concept has failed to reveal a clear or consistent pattern of results. Piaget found that 8-12-month-old infants would make perserverative errors; his explanation for this phenomenon was that the infant's concept of the object was contextually dependent on his or her actions. Some studies designed to test Piaget's explanation have replicated Piaget's basic finding, yet many have found no preference for the A location or the B location or an actual preference for the B location. More recently, researchers have attempted to uncover the causes for these results concerning the A-not-B error. Again, however, different studies have yielded different results, and qualitative reviews have failed to yield a consistent explanation for the results of the individual studies. This state of affairs suggests that the phenomenon may simply be too complex to be captured by individual studies varying 1 factor at a time and by reviews based on similar qualitative considerations. Therefore, the current investigation undertook a meta-analysis, a synthesis capturing the quantitative information across the now sizable number of studies. We entered several important factors into the meta-analysis, including the effects of age, the number of A trials, the length of delay between hiding and search, the number of locations, the distances between locations, and the distinctive visual properties of the hiding arrays. Of these, the analysis consistently indicated that age, delay, and number of hiding locations strongly influence infants' search. The pattern of specific findings also yielded new information about infant search. A general characterization of the results is that, at every age, both above-chance and below-chance performance was observed. That is, at each age at least 1 combination of delay and number of locations yielded above-chance A-not-B errors or significant perseverative search. At the same time, at each age at least 1 alternative combination of delay and number of locations yielded below-chance errors and significant above-chance correct performance, that is, significantly accurate search. These 2 findings, appropriately elaborated, allow us to evaluate all extant theories of stage 4 infant search. When this is done, all these extant accounts prove to be incorrect. That is, they are incommensurate with one aspect or another of the pooled findings in the meta-analysis. Therefore, we end by proposing a new account that is consistent with the entire data set.

Attention↗
PubMed1987

Young children's sensitivity to logical necessity in their inferential search behavior.

Young children's ability to evaluate the logical necessity of 2 types of inferences was studied in 2 experiments involving 68 3-7-year-olds. Children searched the doors of model houses in order to determine whether a house matched a description specifying certain numbers and types of occupants. A search task used in Experiments 1 and 2 allowed children to search for additional information if initial information was insufficient to support a logically necessary inference about whether the house was correct or incorrect. A judgment condition used in Experiment 2 required a "can't tell" response to insufficient information. Even 3-year-olds showed some ability to evaluate the logical necessity of an inference that confirmed a house was correct. Developmental changes involved increased reliability of individuals' performance and increased range of application of children's inference evaluation procedures to include more difficult, disconfirmatory inferences and cases where greater certainty in reasoning seemed to be required. Results are discussed in terms of an account of the gradual development and consolidation of an ability to evaluate the necessity of inferences, perhaps first apparent in preschoolers' sensitivity to conditions of sufficient and insufficient information in information-acquisition problems.

Age Factors↗
PubMed1986

Early understanding of mental entities: a reexamination of childhood realism.

Real physical objects (e.g., a chair) can be distinguished from mental entities (e.g., a thought about a chair) on the basis of a number of criteria. 3 of these are behavioral-sensory evidence--whether the entity can be seen, touched, and physically acted upon; public existence--whether other persons experience the entity; and consistent existence--whether the entity consistently exists over time. Two studies tested 3-5-year-old children's ability to distinguish real versus mental entities on the basis of these criteria and to categorize such entities suitably. Even 3-year-olds were able to judge real and mental entities appropriately on the basis of the 3 criteria, to sort such entities as explicitly real and not-real, and to provide cogent explanations of their choices as well. A further distinction between real and mental entities is that mental entities can be about physically impossible, nonexistent things (e.g., a dog that flies). A third study demonstrated that 3-5-year-olds also appreciated this distinction. Taken together, these results contradict a common characterization of the young child as unaware of the fundamental ontological distinction between the internal mental world and objective reality. The implications of these findings are discussed for 3 other bodies of research: Piaget's characterization of young children as realists, Keil's theory of ontological development, and recent research on children's understanding of the mind.

Child Development↗
PubMed1985

Comprehension monitoring in preschool children.

This study examined the ability of 2 1/2-4 1/2-years-olds to recognize comprehension difficulties and to implement strategies for resolving them. In the course of a play interaction, an adult female experimenter made a series of requests, some of which were designed to be difficult for the child to understand or to execute. Children's responses to these requests were compared with their responses to control requests that were easy to comprehend and comply with 3-year-olds exhibited appropriate and selective monitoring responses for some kinds of problems but not others, while 4-year-olds displayed discriminative monitoring for all types of problems presented. In contrast to previous experimental findings, these results indicate that young children are capable of detecting a variety of comprehension problems and possess appropriate strategies for resolving these difficulties with a partner in communication.

Child Development↗
PubMed1983

Selective information use and perseveration in the search behavior of infants and young children.

Two experiments examined the early development of selective information use in search. The first experiment tested 9- and 16-month-olds on a modification of Piaget's Stage IV object permanence task. It examined infants' use of information from previous experiences with an object (prior information) and from the most recent hiding (current information) to locate a hidden object. In the second experiment, 2-, 2 1/2-, and 4-year-old children received these same sources of information along with new forms of prior and current information: information about the typical locations of objects (location specificity) and verbal information. No systematic perseveration was observed at 9 months, although previous findings related to perseveration were replicated. Perseveration was found at 16 months, but there was also evidence of selectivity at that age. When errors occurred, they tended to be to the prior location, but they were infrequent in comparison to correct searches at the current location. The preschoolers, while continuing to show perseveration, were more consistently selective than the infants. They also showed considerable generality in extending their selectivity to new sources of information.

Age Factors↗
PubMed1982

Children's developing conceptions of the mind and brain.

Previous investigators have examined children's knowledge about particular cognitive performances such as metamemory, or particular mental acts, such as dreams. The present research adds a new dimension by considering children's concepts of the mind as a whole. The development of concepts of both the mind and brain is examined in subjects from preschool age through adulthood. Evidence is presented to show that by ages 4 and 5 years children commonly regard the brain as an internal mindlike entity associated with a class of distinctly mental acts. This runs counter to previous characterizations of young children as failing to distinguish mental from overt behavioral acts. Young children begin with undifferentiated conceptions of the mind and brain. Both entities are regarded as necessary for mental, but not sensory-motor actions. In subsequent developments, the concepts of the mind and brain are differentiated along 2 lines. Ontologically, the mind is distinguished by its immateriality; functionally, the brain is distinguished by its involvement in bodily actions. The development of knowledge about the brain is discussed with respect to acquiring "popular" and "technical" definitions. The results are regarded as contributing toward understanding how children come to organize information about the mental world as a whole.

Adult↗
PubMedDate not supplied

Young children's understanding of perception, desire, and emotion.

Very young children seem to know that people experience several mental states: desires, perceptions, emotions. In three studies, we investigated 2- and young 3-year-olds' judgments and communications about how these states connect together in people's lives and minds. Two experimental studies with 56 participants demonstrated young children's understanding of at least one set of connections: In appropriate circumstances, a person's perception of desirable or undesirable objects leads to related emotional experiences. A complementary investigation of four young children's everyday conversations demonstrated their awareness of and expression of several additional connections between people's desires, perceptions, and emotions.

Child Development↗
PubMedDate not supplied

Thinking about the past: early knowledge about links between prior experience, thinking, and emotion.

In two studies the authors investigated the situations where 3- to 7-year-olds and adults (N = 152) will connect a person's current feelings to the past, especially to thinking or being reminded about a prior experience. Study 1 presented stories featuring a target character who felt sad, mad, or happy after an event in the past and who many days later felt that same negative or positive emotion upon seeing a cue related to the prior incident. For some story endings, the character's emotion upon seeing the cue matched, or was congruent, with the current situation, whereas for others, the emotion mismatched the present circumstances. Participants were asked to explain the cause of each character's current feelings. As a further comparison, children and adults listened to behavior cuing stories and provided explanations for characters' present actions. Study 2 presented emotional scenarios that varied by emotion-situation fit (whether the character's emotion matched the current situation), person-person fit (whether the character's emotion matched another person's), and past history information (whether information about the character's past was known). Results showed that although there were several significant developments with increasing age, even most 3-year-olds demonstrated some knowledge about connections between past events and present emotions and between thinking and feeling. Indeed, children 5 years and younger revealed strikingly cogent understanding about historical-mental influences in certain situations, especially where they had to explain why a person, who had experienced a negative event in the past, was currently feeling sad or mad in a positive situation. These findings help underwrite a more general account of the development of children's coherent understandings of life history, mind, and emotion.

Affect↗
PubMedDate not supplied

Meta-analysis of theory-of-mind development: the truth about false belief.

Research on theory of mind increasingly encompasses apparently contradictory findings. In particular, in initial studies, older preschoolers consistently passed false-belief tasks-a so-called "definitive" test of mental-state understanding-whereas younger children systematically erred. More recent studies, however, have found evidence of false-belief understanding in 3-year-olds or have demonstrated conditions that improve children's performance. A meta-analysis was conducted (N = 178 separate studies) to address the empirical inconsistencies and theoretical controversies. When organized into a systematic set of factors that vary across studies, false-belief results cluster systematically with the exception of only a few outliers. A combined model that included age, country of origin, and four task factors (e.g., whether the task objects were transformed in order to deceive the protagonist or not) yielded a multiple R of .74 and an R2 of .55; thus, the model accounts for 55% of the variance in false-belief performance. Moreover, false-belief performance showed a consistent developmental pattern, even across various countries and various task manipulations: preschoolers went from below-chance performance to above-chance performance. The findings are inconsistent with early competence proposals that claim that developmental changes are due to tasks artifacts, and thus disappear in simpler, revised false-belief tasks; and are, instead, consistent with theoretical accounts that propose that understanding of belief, and, relatedly, understanding of mind, exhibit genuine conceptual change in the preschool years.

Child↗
PubMedDate not supplied

Theory of mind and conceptual change.

We agree with the commentaries by Scholl and Leslie, and also by Moses, that the meta-analytic findings do not definitively rule out early competence accounts. But they do make extant versions of such accounts increasingly unlikely. In particular, the meta-analytic findings argue against executive function expression accounts, including the Theory-of-Mind Mechanism/Selection Processor account advocated by Scholl and Leslie. Specifically, Scholl and Leslie articulate two explicit predictions of their account: that task manipulations that attenuate inhibitory demands should differentially advantage older children, and that theory-of-mind developments should occur with consistent timetables. Both of these specific predictions are clearly contradicted, not supported, by the meta-analytic findings.

Child↗