What is the Inventory of Student Evolution Acceptance (I-SEA) Measuring? A Factor Analytic Comparison of Multiple Competing Hypotheses in Practicing Science Teachers and Undergraduate Science Non-Majors

The Inventory of Student Evolution Acceptance (I-SEA) was developed to provide fine-grained measures of evolution acceptance in populations with moderate-to-high levels of biological sciences understanding. Although the I-SEA has been used extensively since its inception, understanding of how its 24 items function to produce subscales is still lacking. Current work with the I-SEA has used the original three sub-scales for acceptance of macroevolution, microevolution, and human evolution. However, recent work suggests that the I-SEA has item valence effects which need to be considered. The goal of this work is to understand these valence effects and how they interact with the original three-dimensional conceptualization. Through comparison of how the I-SEA functions with practicing K-16 science teachers and undergraduate science non-majors, we found that a six-dimensional structure which considers both type of evolution and item valence provides the best explanation of the data in both cases. However, item valence effects were more pronounced in the undergraduate students. Through the lens of motivated inference, we hypothesize that the differential emotional burden between accepting facts about evolution and rejecting non-scientific ideas about evolution is greater in populations with more heterogenous views about the theory of evolution, and so considering item valence becomes increasingly important for measurement in these populations. Explanation of these valence effects through the lens of motivated inference lends itself to a definition of evolution acceptance based on induced emotional burden associated with accepting facts or rejecting non-scientific ideas related to the theory of evolution.