What can be learned from laypersons’ scientific practices in everyday life: a perspective on causal reasoning

This is the authors' abstract. We don't add key points for this paper.

Science education aims to cultivate ‘competent outsiders’ – individuals who apply scientific reasoning in real-world contexts. Analysing public engagement with science provides insights into how real-world science is intuitively used and its effect on decision-making. Beyond identifying credible information sources, scientific engagement involves reasoning about causal relationships and underlying mechanisms. This study examines how cancer patients undergoing chemotherapy integrate scientific knowledge through mechanistic reasoning. Data from medical records and surveys captured reasoning on causal phenomena, decision-making self-efficacy, and emergency room (ER) visits. Findings revealed the prominence of scientific reasoning, with patients constructing either parallel or interconnected causal relationships between cause and effect. The identified causal pathways did not indicate greater or lesser accuracy but rather illustrated how laypersons integrate their scientific reasoning into a causal structure that supports decision-making. Some patients incorporated mechanistic components into their causal reasoning structures; these patients demonstrated higher decision-making self-efficacy and had fewer ER visits, underscoring the role of mechanistic reasoning in effective functional decision-making. These findings demonstrate that laypersons engage in scientific reasoning in ways that include both systems and mechanistic perspectives, highlighting the potential effect of such engagement on decision-making. Implications for science education, particularly the integration of mechanistic reasoning with systems thinking, are discussed.