High School Students’ Causal Reasoning and Molecular Mechanistic Reasoning About Gene-Environment Interplay After a Semester-Long Course in Genetics

Abstract

This study provides insights into high school students’ (n = 47, age: 16–17 years) molecular mechanistic reasoning about gene-environment interplay. Analyses distinguished between causal and mechanistic reasoning and focused on three interrelated molecular mechanisms of gene-environment interplay. As a main finding, few high school students showed molecular mechanistic reasoning about the environment (13%) and gene-environment interplay (13%) because the genetic and environmental mechanisms had to be inferred from the materials. In contrast, most students focused on information presented in the materials, which they reproduced for causal reasoning about food (21%), mechanistic reasoning about the biochemical pathway (11%), and an unintegrated (23%) or integrated combination (17%) of both types of reasoning. Furthermore, we interviewed a subgroup of seven students about the gene-environment interplay model of trait formation to validate our interpretations. The model visualizes relationships between gene, gene product, trait and environment. Students’ fragmented knowledge of gene-environment interplay rendered use of the model difficult for mechanistic reasoning because students rarely acknowledged enzymes as mediators between genes and traits and the role of proteins in trait formation. We discuss “tracing trait formation” as a teaching learning strategy and recommend using the gene-environment interplay model of trait formation for implementing this strategy in the classroom.