Vaccine hesitancy and SCAM-use: the anti-scientific mindset

Use of so-called alternative medicines (SCAM) is, as we have frequently discussed on this blog, associated with an anti-vax attitude or vaccine hesitancy. However, the nature of—and reasons for—this association are  not entirely clear, not least because both SCAM and vaccine hesitancy are complex, heterogeneous phenomena.

A recent study aimed to determine which aspects of SCAM predict vaccine hesitancy and to probe the psychological roots of their association. In a two-stage survey (N1 = 1905, N2 = 1443), participants from Argentina, Germany and the USA reported vaccine/SCAM health behaviors, intentions and beliefs. They also responded to scales probing attitudes to science, individual differences in cognitive styles, and anomalous beliefs.

An Item-Response Theoretic model of vaccine responses revealed that, outside of either total acceptance or outright refusal of vaccines, hesitancy reflected a gap between past vaccination behaviors and future behavioral intentions. More than SCAM-use, vaccine hesitancy was predicted by SCAM-relevant health beliefs. An oppositional view of natural vs. biomedical care was central in this regard. Unscientific mindsets—both in attitudes to expertise and in anomalous beliefs—underpinned the psychological similarity of SCAM beliefs and vaccine hesitancy.

The authors concluded that the relationship between SCAM and vaccine hesitancy is primarily a matter of health-relevant beliefs centered on natural vs. scientific medicine. This relationship—and in particular, a gap between past vaccine behaviors and future be havioral intentions—reflects fundamentally unscientific mindsets. Thus, a key challenge in addressing this form of vaccine hesitancy is one of perspective taking: Scientists must find persuasive reasons to vaccinate which appeal to people who do not see science as the main route to medical knowledge.

These findings should seem fairly obvious to those of us who have followed the discussions on this blog and elsewhere around vaccines and vaccinations. In the present study, belief in ‘naturalness’ predicted vaccine acceptance – and did so consistently across countries – more than other health beliefs. The associations between vaccine acceptance and SCAM were not strongly related to  sociodemographic factors. The only regular pattern was for gender, with women being both more vaccine resistant and more pro-SCAM than men.

Negative attitudes towards vaccines and belief in ‘naturalness’ were associated with a cluster of ‘anti-expert’ variables including distrust in science. Vaccine resistance was also associated with a range of anomalous beliefs or biased belief updating styles. These negative attitudes to scientific sources of information and unscientific belief contents are different aspects of an unscientific mindset.

I think, this makes sense and seems to confirm previous findings about the association between SCAM-use and vaccine hesitancy: the two are linked indirectly by a common denominator.