Theoretical justifications for using word-based stimuli in the implicit association test for physical activity

Over the past decade, researchers have increasingly drawn on dual-process models to explain why individuals fail to translate physical activity intentions into sustained behavior. According to these models, a person's behavior can be influenced by two different types of process; first, reflective processes (e.g., intention) and, second, automatic processes (e.g., habit). The IAT offers researchers a means of capturing automatic evaluative associations that self-report measures cannot access. However, the choice of either word-based or picture-based stimuli in physical activity IAT can meaningfully affect the sensitivity, reliability, and cross-cultural applicability of measurements. This article presents my perspective on the theoretical and methodological justification for recommending word-based stimuli as a reasonable default for assessing generalized implicit attitudes in physical activity IAT, drawing on empirical work in cognitive psychology, health behavior research, and exercise psychology. I argue that word-based stimuli may tend to produce more consistent response times, somewhat higher internal reliability, and lower interpretive variability than picture-based stimuli, while emphasizing that this evidence is largely indirect, deriving from studies that did not directly compare the two modalities within the same design. I then outline future applications of word-based IAT for advancing both understanding and intervention design in physical activity.