Toddler toy play evolves in a predictable manner and provides a valid, nonverbal measure of cognitive function unbiased by social behaviors. Research on prenatal maternal stress (PNMS) indicates that exposure to stress in utero results in developmental deficits. We hypothesized that children exposed to high objective PNMS from a natural disaster…

Toddlers' symbolic understanding of iconic models was assessed through 2 comprehension-based tasks: 1 based on looking and 1 requiring manual selection of the target object. Toddlers received either iconic models or photographs of models as the symbolic referent. Overall, 18-month-olds performed poorly, and both 22- and 26-month-olds performed…

We introduce the thematic collection by noting some striking similarities in the cognitive abilities of human infants and nonhuman primates. What are the implications of these similarities for our comprehension of human infant cognition? After providing a brief historical and conceptual background on comparative behavioral research, we discuss how…

The experiment reported here investigated infants' concept of intention, as well as the relation among intention understanding, general productive vocabulary, and internal state language production during the 2nd year. Results from an imitation task indicated that 18-month-olds are better able to differentiate between intentional and accidental…

We investigated the developmental trajectory of nonadjacent dependency learning in an artificial language. Infants were exposed to 1 of 2 artificial languages with utterances of the form [aXc or bXd] (Grammar 1) or [aXd or bXc] (Grammar 2). In both languages, the grammaticality of an utterance depended on the relation between the 1st and 3rd…