Where do Traits Come From? A Storybook Intervention Helps Children Understand Genetic Versus Social Inheritance

• In Event: STEM Storybooks as a Platform for STEM Learning

Abstract

Across countries, education standards frequently indicate that children should begin learning about biological inheritance from early in schooling. For example, the Next Generation Science Standards stipulate that by second grade, children should understand that offspring resemble–but are not identical to–their parents. By fifth grade, they are expected to understand that while some traits are inherited, others derive from learning and experience. However, due to assumptions about children’s conceptual limitations, students are not introduced to genes—the mechanism that underlies the inheritance of traits—until eighth grade. Such piecemeal non-mechanistic instructional approaches may explain why children often develop misunderstandings about genetic inheritance that can endure into adulthood, for instance, that offspring always look more like mothers than fathers, resemble their biological parents more than adoptive parents regardless of trait, and that parents can choose their children’s traits (e.g., Solomon & Johnson, 2000; Weissman & Kalish, 1999; see Ware & Gelman, 2013, on adults).

Related research indicates that children benefit from causal-mechanistic explanations of scientific concepts when they are presented via child-friendly narratives. This study therefore examined whether, despite its abstract nature, young children can learn and generalize a mechanistic explanation about genes and their role in biological inheritance from a custom storybook intervention. Seven- and 8-year-olds (n=21) participated in a pretest-posttest design that involved three posttest assessments. The storybook depicted an explanatory conversation between two children about a kitten that connected various ideas including that genes: are located inside the cells of all bodies; are inherited from both birth parents not adoptive parents; play a greater causal role in physical than learned traits. Using age-appropriate language, the storybook also explained that gene expression is often but not always predictable and is never dictated by parent preference. The text was highly expository, substantially differing in style and content from most children’s storybooks and those previously used to teach young children about evolutionary mechanisms (e.g., Kelemen, et al., 2014; see Figure 1).

Participants’ responses on the assessments were coded into six levels of increasing inheritance understanding (see Figure 2). Few children understood genetic inheritance at pretest. However, after the intervention, most children demonstrated advanced levels of understanding. Repeated measures ordinal logistic regression confirmed that children learned from the intervention, Wald χ2(3) = 33.13, p < 0.001–the odds of displaying a higher level of inheritance understanding increased seventeen-fold from pretest to comprehension test, OR = 17.60, p < .001. Furthermore, performance on the comprehension posttest and both generalization posttests did not differ, ps > 0.12, indicating that children successfully generalized the explanation whether they were considering another animal or humans.

In conclusion, while conventional wisdom might suggest that mechanistic explanations of biological inheritance are too abstract for children, the present results suggests that there is no need to delay introducing them until middle school. Young children can understand and generalize them when they are taught via a narrative. Indeed, exposure to such mechanistic explanations may reduce the risk that incorrect ideas become entrenched in ways that may hamper longer-term understanding.

Authors

• Sarah A Brown, Boston University
  Presenting Author

• Natalie Emmons, Boston University
  Non-Presenting Author

• Rebecca S Schillaci, Education Development Center
  Non-Presenting Author

• Meia Chita-Tegmark, Tufts University
  Non-Presenting Author

• Deb Kelemen, Boston University
  Non-Presenting Author