Numerate people are less likely to be biased by regular science reporting: the critical roles of scientific reasoning and causal misunderstanding.

Numerate people tend to make more informed judgments and decisions because they are more risk literate (i.e., better able to evaluate and understand risk). Do numeracy skills also help people understand regular science reporting from mainstream news sources? To address this question, we investigated responses to regular science reports (e.g., excerpts from CNN Health), testing a cognitive model linking numeracy, scientific reasoning, judgment biases, and causal theory errors (i.e., interpreting correlational information as causal). In Study 1 (n = 200), structural equation modeling indicated that more numerate people were less likely to exhibit judgment biases because they were better at scientific reasoning, which helped them avoid causal misinterpretations. Study 2 (n = 342) cross-validated findings from Study 1, indicating that the link between numeracy and scientific reasoning was also associated with improved cognitive self-assessment (e.g., reduced overconfidence on comprehension judgments). Results indicate that more numerate people may generally be less likely to confuse correlation and causation in regular science reporting. Results also suggest that numerate people are more likely to have acquired scientific reasoning skills that more generally support risk literacy and knowledge acquisition, consistent with Skilled Decision Theory. Discussion focuses on implications for risk literacy research, and includes a Risk Literacy Difficulty Analysis indicating that more than half of the USA adult population may be likely to misunderstand common types of regular science reports.