Specifying the role of function in infant categorization

"Shape bias" goes social: Children categorize people by weight rather than race

Children tend to categorize novel objects according to their shape rather than their color, texture, or other salient properties-known as "shape bias." We investigated whether this bias also extends to the social domain, where it should lead children to categorize people according to their weight (their body shape) rather than their race (their skin color). In Study 1, participants (n = 50 US 4- and 5-year-olds) were asked to extend a novel label from a target object/person to either an object/person who shared the target's shape/weight, color/race, or neither. Children selected the shape-/weight-matched individual over the color-/race-matched individual (dobjects  = 1.58, dpeople  = 0.99) and their shape biases were correlated across the two domains. In Study 2, participants (n = 20 US 4- and 5-year-olds) were asked to extend a novel internal property from a target person to either a person who shared the target's weight, race, or neither. Again, children selected the weight-matched individual (d = 1.98), suggesting they view an individual's weight as more predictive of their internal properties than their race. Overall, results suggest that children's early shape bias extends into the social domain. Implications for weight bias and early social cognition are discussed. RESEARCH HIGHLIGHTS: Preschoolers extend novel labels based on people's weight rather than their race. Preschoolers infer internal features based on people's weight rather than their race. Shape biases are present, and correlated, across the social and object domains.

The road to conventional tool use: Developmental changes in children's material engagement with artifacts in nursery school

The development of tool use in early childhood is a topic of continuing interest in developmental psychology. However, the lack of studies in ecological settings results in many unknowns about how children come to use artifacts according to their cultural function. We report a longitudinal study with 17 sociodemographically diverse children (8 female) attending a nursery school in Madrid (Spain) and their two adult female teachers. Using mixed-effects models and Granger causality analysis, we measured changes in the frequency and duration of children's object uses between 7 and 17 months of age and in the directional influences among pairs of behaviors performed by teachers and children. Results show a clear shift in how children use artifacts. As early as 12 months of age, the frequency of conventional uses outweighs that of all other types of object use. In addition, object uses become shorter in duration with age, irrespective of their type. Moreover, certain teachers' nonlinguistic communicative strategies (e.g., demonstrations of canonical use and placing gestures) significantly influence and promote children's conventional tool use. Findings shed light on how children become increasingly proficient in conventional tool use through interactions with artifacts and others in nursery school.

The development of categorisation and conceptual thinking in early childhood: methods and limitations

We present a systematic and qualitative review of academic literature on early conceptual development (0–24 months of age), with an emphasis on methodological aspects. The final sample of our review included 281 studies reported in 115 articles. The main aims of the article were four: first, to organise studies into sets according to methodological similarities and differences; second, to elaborate on the methodological procedures that characterise each set; third, to circumscribe the empirical indicators that different sets of studies consider as proof of the existence of concepts in early childhood; last, to identify methodological limitations and to propose possible ways to overcome them. We grouped the studies into five sets: preference and habituation experiments, category extension tasks, object sorting tasks, sequential touching tasks and object examination tasks. In the “Results” section, we review the core features of each set of studies. In the “Discussion” and “Conclusions” sections, we describe, for one thing, the most relevant methodological shortcomings. We end by arguing that a situated, semiotic and pragmatic perspective that emphasises the importance of ecological validity could open up new avenues of research to better understand the development of concepts in early childhood.

Funcionamientos Inferenciales en Niños Caminadores: un Acercamiento al Microdesarrollo en una Tarea de Resolución de Problemas

Se exponen los resultados de un estudio sobre la emergencia de la capacidad de niños caminadores para resolver problemas, centrado en la manera como niños de 25 meses de edad acceden a la comprensión de un problema de compuertas, cuya solución les exige funcionamientos inferenciales distintos. Se aplicó una metodología microgenética, en la cual se utiliza una situación de resolución de problemas (SRP), en tres ensayos de una misma sesión de observación. El análisis se dirige a las variaciones interindividuales, a partir de las cuales se identifican tendencias en los desempeños de los niños. Los resultados ponen en evidencia la capacidad resolutoria de niños caminadores, manifestada en acciones sistemáticas, organizadas, automotivadas y en el uso de procesos inferenciales complejos.

Development of categorization in infancy: advancing forward to the animate/inanimate level

Three experiments are reported on the development of object categorization skills during the second year of life. Experiment 1 examined whether 14- and 18-month-old infants were capable of performing categorization at the animate/inanimate (A/I) level using a sequential touching task. The 18-month-olds were significantly above chance and the 14-month-olds were also approaching above-chance significance, which is the highest level of inclusiveness ever tested in infancy. In Experiments 2 and 3, 14-month-old infants participated in a sequential touching task in which the part features of animate and inanimate objects were modified, allowing for a test of partonomic (i.e., legs and wheels) vs. taxonomic (i.e., animates and inanimates) categorization. Infants did not favor partonomic categorization, suggesting that A/I categories are not formed solely based on object parts such as legs and wheels.