Two studies examined how children between ages 4 and 6 use body shape (i.e., the waist-to-hip-ratio [WHR]) for sex categorization. In Study 1 (N = 73), 5- and 6-year-olds, but not 4-year-olds, selected bodies with increasingly discrepant WHRs to be "most like a man" and "most like a woman." Similarly, sex category judgments made by 5- and…

Previous looking time studies have shown that infants use the heads of cat and dog images to form category representations for these animal classes. The present research used an eye-tracking procedure to determine the time course of attention to the head and whether it reflects a preexisting bias or online learning. Six- to 7-month-olds were…

Two studies examined the inductive potential of various social categories among 144 kindergarten, 2nd-, and 6th-grade Israeli children from 3 sectors: secular Jews, religious Jews, and Muslim Arabs. Study 1--wherein social categories were labeled--found that ethnic categories were the most inductively powerful, especially for religious Jewish…

How does understanding the decimal system change with age and experience? Second, third, sixth graders, and adults (Experiment 1: N = 96, mean ages = 7.9, 9.23, 12.06, and 19.96 years, respectively) made number line estimates across 3 scales (0-1,000, 0-10,000, and 0-100,000). Generation of linear estimates increased with age but decreased with…

This study examined classifications of attachment in 42-month-old Romanian children (N = 169). Institutionalized since birth, children were assessed comprehensively, randomly assigned to care as usual (CAU) or to foster care, and compared to family-reared children. Attachment classifications for children in foster care were markedly different from…

The transition into school occurs at the intersection of multiple environmental settings. This study applied growth curve modeling to a sample of 1,364 American children, followed from birth through age 6, who had been categorized by their exposure to cognitive stimulation at home and in preschool child care and 1st-grade classrooms. Of special…

Two studies (N = 456) compared the development of concepts of animal species and human gender, using a switched-at-birth reasoning task. Younger children (5- and 6-year-olds) treated animal species and human gender as equivalent; they made similar levels of category-based inferences and endorsed similar explanations for development in these 2…

Spontaneous transfer of learning is often difficult to elicit. This finding may be widespread partly because pretests proactively interfere with transfer. To test this hypothesis, 7-year-olds' transfer was examined across 2 numerical tasks (number line estimation and categorization) in which similar representational changes have been observed. As…

Whereas traditional theories of gender development have focused on individualistic paths, recent analyses have argued for a more social categorical approach to children's understanding of gender. Using a modeling paradigm based on K. Bussey and A. Bandura (1984), 3 experiments (N = 62, N = 32, and N = 64) examined preschoolers' (M age = 52.9…

Three experiments explored the significance of deontic properties (involving rights and obligations) in representations of social categories. Preschool-aged children (M = 4.8), young school-aged children (M = 8.2), and adults judged the centrality of behavioral, psychological, and deontic properties for both familiar (Experiments 1 and 2, Ns = 50…

Interpersonal dynamics within friendships were observed in a sample of 120 (60 male, 60 female) ethnically diverse 16- and 17-year-old adolescents characterized as persistently antisocial, adolescent-onset, and normative. Dyadic mutuality and deviant talk were coded from videotaped friendship interactions. Persistently antisocial adolescents…

Infants exposed to a set of artificially-created face stimuli having distinct mean and modal prototypes showed a pattern of behavior predicted by category abstraction models. Infants appeared to abstract, at the time of learning, a feature-count summary of the category displayed. (Author/RH)

Two experiments investigated infants' use of structural relations in dividing schematic drawings of animals into categories. Results demonstrated subjects' sensitivity to structural information like that thought by Rosch (1978) to exist in the natural world and their ability to segregate items into categories on the basis of clusters of correlated…

The ability of 1- to 3-year-olds to conceptually interrelate objects was studied among eight children each at 12, 18, 24, 30, and 36 months who were given seven free classification tasks containing a scrambled array of eight objects from two classes. Spontaneous manipulations of the subjects were analyzed. (Author/RH)

In one of three studies, preschoolers judged that items that shared material properties, such as metal composition, would share dispositional properties, such as corrodibility in water, and that items of the same object type, such as baseball bats, would share functional properties, such as the ability to accelerate a baseball. (BC)