The developmental roots of environmental stewardship: Childhood and the climate change crisis.

Childhood presents heightened vulnerabilities and unique opportunities in the context of climate change. Even very young children view the environment as a moral concern. Furthermore, early life experiences can lay the groundwork for a lifetime of environmental stewardship. Exposure to nature and parental eco-friendly behaviors are each predictive of children's commitment to environmental engagement later in life. However, these early inclinations give way to decreasing environmental concern in adolescence. Research is beginning to shift from a framework that emphasizes children's status as victims of the climate change crisis to one that instead underscores their role as agents of change.

Labels affect preschoolers' tool-based scale errors.

Scale errors offer a unique context in which to examine the interdependencies between language and action. Here, we manipulated the presence of labels in a tool-based paradigm previously shown to elicit high rates of scale errors. We predicted that labels would increase children's scale errors with tools by directing attention to shape, function, and category membership. Children between the ages of 2 and 3years were introduced to an apparatus and shown how to produce its function using a tool (e.g., scooping a toy fish from an aquarium using a net). In each of two test trials, children were asked to choose between two novel tools to complete the same task: one that was a large non-functional version of the tool presented in training and one novel functional object (different in shape). A total of four tool-apparatus sets were tested. The results indicated that without labels, scale errors decreased over the two test trials. In contrast, when labels were present, scale errors remained high in the second test trial. We interpret these findings as evidence that linguistic cues can influence children's action-based errors with tools.

Word comprehension and production asymmetries in children and adults.

Two studies investigated differences in the comprehension and production of words in 2-year-old children and adults. Study 1 compared children's speaking and understanding of the names of 12 novel objects presented over three weekly sessions. Study 2 tested adults' performance under similar training and testing conditions over two sessions. The findings indicated a comprehension advantage for both age groups. A fine-grained temporal analysis of individual words revealed that acquisition does not resemble a linear stage-wise progression from comprehension to production. Rather, dimensions of lexical knowledge develop at different rates, with words acquired, lost, and maintained over the course of learning. The findings support a dynamic and graded view of lexical processing and have implications for understanding what it means to know a word.

The shape-bias in Spanish-speaking children and its relationship to vocabulary.

Considerable research has demonstrated that English-speaking children extend nouns on the basis of shape. Here we asked whether the development of this bias is influenced by the structure of a child's primary language. We tested English- and Spanish-speaking children between the ages of 1 ; 10 and 3 ; 4 in a novel noun generalization task. Results showed that English learners demonstrated a robust shape-bias, whereas Spanish learners did not. Further, English-speaking children produced more shape-based nouns outside the laboratory than Spanish-speaking children, despite similar productive vocabulary sizes. We interpret the results as evidence that attentional biases arise from the specifics of the language environment.

Fast mapping skills in the developing lexicon.

PURPOSE: This preliminary investigation was a longitudinal study of fast mapping skills in normally developing children, 16-18 months of age. The purpose was to examine the effects of practice on the accessibility of words in lexical memory. METHOD: Eight children were taught the names of 24 unfamiliar objects over 12 weekly training sessions. The amount of practice children had with individual words varied as a function of session. Data were compared to a control group of children-matched on productive vocabulary-who were exposed to the same experimental words at the first and last sessions only. RESULTS: The results showed that for children in the experimental group, extended practice with a novel set of high-practice words led to the rapid acquisition of a second set of low-practice words. Children in the control group did not show the same lexical advantage. CONCLUSIONS: The data suggest that learning some words primes the system to learn more words. Vocabulary development can thus be conceptualized as a continual process of fine-tuning the lexical system to enable increased accessibility to information. Implications for the treatment of children with word-finding difficulties are considered.