You Get What You Need: An Examination of Purpose-Based Inheritance Reasoning in Undergraduates, Preschoolers, and Biological Experts

This set of seven experiments examines reasoning about the inheritance and acquisition of physical properties in preschoolers, undergraduates, and biology experts. Participants (N = 390) received adoption vignettes in which a baby animal was born to one parent but raised by a biologically unrelated parent, and they judged whether the offspring would have the same property as the birth or rearing parent. For each vignette, the animal parents had contrasting values on a physical property dimension (e.g., the birth parent had a short tail; the rearing parent had a long tail). Depending on the condition, the distinct properties had distinct functions (“function-predictive”) were associated with distinct habitats (“habitat-predictive”), or had no implications (“non-predictive”). Undergraduates' bias to view properties as inherited from the birth parent was reduced in the function- and habitat-predictive conditions. This result indicates a purpose-based view of inheritance, whereby animals can acquire properties that serve a purpose in their environment. This stance was not found in experts or preschoolers. We discuss the results in terms of how undergraduates' purpose-based inheritance reasoning develops and relates to larger-scale misconceptions about Darwinian evolutionary processes, and implications for biology education.