The ability to consider multiple possibilities forms the basis for a wide variety of human-unique cognitive capacities. When does this skill develop? Previous studies have narrowly focused on children's ability to prepare for incompatible future outcomes. Here, we investigate this capacity in a causal learning context. Adults (N = 109) and 18- to…

During communication, conversational partners should offer as much information as is required and relevant. For instance, the statement "Some Xs Y" is infelicitous if one knows that all Xs Y. Do children understand the link between speaker knowledge and utterance strength? In Experiment 1, 5-year-olds (N = 32) but not 4-year-olds…

Children's sensitivity to the quality of epistemic reasons and their selective trust in the more reasonable of 2 informants was investigated in 2 experiments. Three-, 4-, and 5-year-old children (N = 90) were presented with speakers who stated different kinds of evidence for what they believed. Experiment 1 showed that children of all age groups…

Category-based induction requires selective use of different relations to guide inferences; this article examines the development of inferences based on ecological relations among living things. Three hundred and forty-six 6-, 8-, and 10-year-old children from rural, suburban, and urban communities projected novel "diseases" or "insides" from one…

The neurodevelopmental sequelae of early deprivation were examined by testing (N = 132) 8- and 9-year-old children who had endured prolonged versus brief institutionalized rearing or rearing in the natal family. Behavioral tasks included measures that permit inferences about underlying neural circuitry. Children raised in institutionalized…

This study describes the development of social reasoning in school-age children. An irony task is used to assess 5-, 7-, and 9-year-olds' (N = 72) and adults' (N = 24) recursive understanding of others' minds. Guttman scale analysis demonstrates that in order to understand a speaker's communicative intention, a child needs to recognize the…

This study tests the firm distinction children are said to make between living and nonliving kinds. Three, 4-, and 5-year-old children and adults reasoned about whether items that varied on 3 dimensions (alive, face, behavior) had a range of properties (biological, psychological, perceptual, artifact, novel, proper names). Findings demonstrate…

Assessed 3- to 7-year-old children's sensitivity to logical necessity by contrasting performance in insufficient and sufficient information conditions. A search task used in Experiments 1 and 2 allowed children to search for additional information in insufficient conditions. A judgement condition used in Experiment 2 required a "can't tell"…

Nine- to 16-month-old infants explored pairs of novel toys in 2 conditions: violated expectation, in which the first toy produced an interesting nonobvious property and the second toy did not; and interest control, in which neither toy produced the interesting property. Infants persistently attempted to reproduce the interesting property in the…

Two experiments assessed preschoolers' understanding of objects possessing a property in part only and their understanding that different parts of an object may possess opposed properties. Results suggested that children as young as 3 years possess a sophisticated ability to reason about the heritability of properties from parts to wholes.…

In Study 1, 10-, 13-, and 16-year-olds were assigned to conditions in which they were instructed to think logically and provided alternative antecedents to the consequents of conditional statements. Providing alternatives improved reasoning on two uncertain logical forms, but decreased logical responding on two certain forms; logic instructions…

Four experiments studied 4- to 6-year-old children's understanding of inferential reasoning as a source of knowledge. To assess understanding that knowledge of relevant premises leads to knowledge of the conclusion, children had to judge the knowledge of another person, who was presented to the child as being aware of two premises. (Author/BN)

Two experiments demonstrated that by the age of four years, children can use the difference between an object's initial and final state to work out what happens to an object when it changes. In contrast, three-year-old children have difficulty in using the difference between initial and final states to make a causal inference. (RH)

Examined influence of object labels and shape similarity on 16- to 21-month-olds' inferences. Found that infants generalized non-obvious property of unlabeled objects to test objects with highly similar shapes. For objects labeled with novel nouns, infants relied on shape similarity and shared labels to generalize properties. For objects labeled…

Examined 7- to 10-year-olds' ability to acquire a domain-general processing strategy--Control of Variables Strategy (CVS)-- and make valid inferences. Found that with explicit training within domains and probe questions, children could learn and transfer the CVS. Probes without direct instruction did not improve CVS and inferential thinking…