“It’s the X and Y Thing”: Cross-sectional and Longitudinal Changes in Children’s Understanding of Genes

Studies from different theoretical traditions investigating children’s inheritance and genetics concepts have adopted a cross-sectional method. This paper is the first to examine both cross-sectional and longitudinal changes in children’s basic genetic concepts. It forms part of a larger investigation into the development of intuitive inheritance and genetics concepts in childhood. Four age cohorts (4–5 years, 7–8 years, 10–11 years, 14–15 years) were interviewed individually at two measurement occasions (T1, N = 182; T2, N = 164) separated by a 1-year interval. Cross-sectional analyses revealed an increase in children’s knowledge of genetics by 10 years. Between 10 and 14 years, there were fewer changes in the content of children’s knowledge, especially at the level of scientific genetic understanding. There was little evidence of longitudinal changes over the 1-year period. Overall, children may hold an understanding of genetics that is tied to knowledge of inheritance within families. This may pose challenges for acquiring more abstract and formal concepts of genes.