Poster #33 - Preschool Engineers: Children use Relative Rigidity to Decide the Appropriate Material to Build a Bridge

• In Event: 3-003 - Poster Session 09
  In Poster Session: PS 09 Section - Cognitive Processes

Integrative Statement

Three- and four-year-old children can select rigid over non-rigid materials for making a bridge that can support an elephant’s crossing a river (Yang & Gelman, 2017). Since the thickness of the material swatches covaried with rigidity in the previous study, it is uncertain if children did use rigidity as the cue to help them decide. In the present study, the thickness of the test pairs was controlled and it investigated if children could still select the more appropriate material. In the demonstration phase, 21 three- and 28 four-year-old children watched an animation as a builder built a bridge, using either “good stuff” (i.e., plexiglas) or “not good stuff” (i.e., paper). Then they saw an elephant either cross the bridge successfully, when it was constructed from “good stuff”, or fall into the river, when the bridge was made from “not good stuff”. In the memory test, children first identified the materials used in the animations and then recalled the events that occurred when the elephant walked on each kind of bridge. In the experimental test phase, they were shown six pairs of swatches of materials that had either congruent, incongruent, or mixed thickness and asked to select the one that can build the bridge to afford the elephant from each pair. The congruent pairs were: two pairs of materials that are congruent (rigidity can be discerned from the thickness) (Plastic paper (0.025cm) VS. Wood (0.5cm), Plastic paper (0.025cm) VS. Metal (0.15cm)). The incongruent pairs were: Foam (0.2 cm) vs. Wood (0.2 cm); Wool (0.15 cm) vs. Metal (0.15 cm);that are incongruent (rigidity cannot be discerned from the thickness), and two pairs of materials that are mixed (Wool (0.15 cm) VS. Wood (0.2 cm), Foam (0.2 cm) VS. Metal (0.15 cm)) (See Figure 1).
Children who failed the memory test were excluded from the analysis (4 three-year-olds and 5 four-year-olds). In the end, 17 out of 21 3-year-old children (81%) and 23 out of 28 4-year-old (82%) children completely passed the memory test. Given the children who passed the memory test, both 3- (M = 1.47, SD = 0.80) and 4-year-old (M = 1.65, SD = 0.71) children performed better than chance (p = .5) in the incongruent pairs (Chi-square(2, N = 17) = 14.65, p < .001; Chi-square(2, N = 23) = 35.26, p < .001, respectively) and the congruent pairs (3-yr-olds: M = 1.65, SD = 0.70, Chi-square(2, N = 17) = 24.17, p < .001; 4-yr-olds: M = 1.65, SD = 0.71, Chi-square(2, N = 23) = 35.26, p < .001). A Friedman test also revealed that there was no effect for the different thickness conditions (p = .576, two-tailed). Therefore, both three- and four-year-old children could use the relative rigidity and not the thickness to select the appropriate materials to build the bridge to afford a certain weight.

Authors

• Shuqi Yang, University of Hong Kong
  Presenting Author

• Rochel Gelman, Rutgers University
  Non-Presenting Author