Effects of Priming Variability on Children’s Endorsement of Metamorphosis and Evolution

• In Event: 3-134 - The Essence of Biological Categories: Factors Influencing Children’s Sensitivity to Variability and Change

Integrative Statement

Researchers have argued that children have an essentialist view of animal categories, which leads them to underestimate, and sometimes even reject, within-species variation (Shtulman & Schulz, 2008). Psychological essentialism could thus hinder understanding of biological concepts such as evolution by making it difficult for people to appreciate within-species variability, which is integral for understanding natural selection (Shtulman & Calabi, 2012). Scholars have also claimed that essentialist reasoning can hinder children’s understanding of biological changes like metamorphosis (French et al., 2018). To test these claims we recruited 152 children from kindergarten to third grade. We probed their understanding of biological changes such as metamorphosis and evolution after they were exposed to a within-species variability, between-species variability, or a control prime. We hypothesized the within-species variability prime would decrease essentialist reasoning, increasing endorsement of metamorphosis and evolution, whereas the between-species prime would show the opposite effect. Additionally, based on prior work suggesting that children disregard category variability until about second grade (Rhodes & Brickman, 2010), we hypothesized that only the older children would show this effect.

At pretest we asked children to endorse or reject different types of change, including metamorphosis. Then, we primed them either to think about variability within a species, between a species, or provided no prime as a control. Then, we gave children a metamorphosis lesson. Finally, we asked participants to make more endorsements and probed their beliefs about the origin of species. As can be seen in Figure 1, we found that there was an interaction between prime type and grade. As hypothesized, the within-species variability prime led to greater endorsement of metamorphosis, but only among second and third graders, F(1, 120) = 6.58, p = .0122. Counter to our expectations the between-species variability prime had the same effect, F(1, 120) = 4.93, p = .028. We believe this might be due to participants interpreting the between-species variability prime as highlighting within-category variability at a broader category level (i.e., at the level of the biological order). Thus, both conditions show that priming students to think about within-species variability might lead them to endorse metamorphosis more after a lesson.

We also coded children’s explanations about the origin of species following Evans (2000). We found that 25% of children gave evolution-consistent explanations, 18% gave creationist explanations, and 27% referenced spontaneous generation. Additionally, we found a prime by pretest interaction on children’s predicted likelihood of giving an evolution-consistent explanation, F(1, 130) = 4.93, p = .026. As shown in Figure 2, highlighting between-species variability increased the likelihood of providing an evolutionary explanation of the origin of species. A similar but non-significant trend can be seen for the within-species variability prime.

Overall, this study suggests that highlighting both within- and between-species variability can be beneficial during biological instruction. For children who are ready to use this information, priming variability might increase their endorsement of counter-intuitive biological processes such as metamorphosis and evolution. This study provides support for the idea that essentialist reasoning hinders learning in the biological domain.

Authors

• David Menendez, University of Wisconsin-Madison
  Presenting Author

• Karl S. Rosengren, University of Wisconsin-Madison
  Non-Presenting Author

• Martha W Alibali, University of Wisconsin-Madison
  Non-Presenting Author