Understanding responses to different types of conflicting information about cancer prevention

Individuals are regularly exposed to conflicting information about health; however, understanding of how individuals respond to different types of conflicting information is limited.

In total, 1027 US adults were randomly assigned to 1 of 8 conflicting information messages about nutrition and cancer risk, depicting 1/4 conflicting information types (conflict in evidence - sources A and B agree the evidence is mixed; conflict between two expert sources - sources A and B present conflicting evidence about nutrition and cancer risk; conflict within the same expert source - source A changes its own recommendation about the evidence; no conflict control) crossed by 1/2 baseline recommendations with which new information conflicted (limit vs. do not limit red meat intake to reduce cancer risk).

Compared to the control, each conflicting information type led to lower perceived scientific consensus about how much red meat one should eat (p < .001); conflict in evidence (p = .004) and between sources (p = .006) led to lower trust in scientists. Intentions to consume red meat more frequently were higher in the conflicting information conditions than control in the group initially told to "limit red meat" and lower in the "do not limit red meat" group (p = .022). Conflict within the same source led to higher perceived scientific consensus compared to conflict in evidence (p = .007) and between sources (p = .013); it also lowered intentions to consume red meat more frequently compared to conflict in evidence, but only in the "do not limit red meat" condition (p = .033). Conflict in evidence (p = .007) and within the same source (p = .013) increased cancer fatalism compared to conflict between sources.

Conflict in scientific evidence and conflict arising from the same expert source (e.g., a changing public health guideline) may have pernicious effects. Future efforts could investigate how best to publicly communicate these instances of scientific conflict to minimize negative impact.