“Yesterday” I presented some evidence that vaccine attitudes are unrelated to disgust. Today I’ll present some more.
Yesterday’s evidence consisted of a comparison of how disgust sensibilities relate to support for the policy of universal vaccination, on the one hand, and how they relate to a bunch of other policies one would expect either to be disgust driven or completely unrelated to disgust.
It turned out that the disgust-vaccine relationship was much more like the relationship between disgust and policies unaffected by disgust sensitivity—like campaign finance reform and tax increases —than like the relation between disgust and policies like gay marriage and legalization of prostitution. Which is to say, there really wasn’t any meaningful relationship between disgust and attitudes toward mandatory vaccination at all.
Today’s post will use a similar strategy to probe the link (or lack thereof) between disgust and vaccine risk perceptions.
To measure disgust sensitivity, we’ll again use the conventional “pathogen disgust” scale, which other researchers have reported to be correlated—although only weakly and unevenly—with vaccine attitudes.
To measure vaccine risk perceptions, we’ll use the trusty (indeed, some would say miraculously discerning) Industrial Strength Risk Perception Measure.
The ISRPM solicits subjects’ appraisals of “how serious” a risk is on a 0-7 scale. It has been shown to be highly correlated with more fine-grained appraisals of putative risks and even with risk-taking behaviors.
There is a correlation between perceptions of the risk of childhood vaccines, measured with the ISRPM, and the pathogen disgust scale. It is r = 0.17.
Is that big? I don’t think so.
But the more important point is that it is smaller than the correlation between the disgust scale and a host of other risk perceptions relating to activities that no one would think have anything to do with disgust.
These include air plane crashes, elevator accidents, kids downing in swimming pools, and mass shootings.
The correlation between vaccine risks and disgust sensitives was about the same as the correlation between disgust sensitives and fear of artificial intelligence and workplace accidents.
Again, no one believes that these other concerns are driven by disgust. They are just a random collection of risk perceptions that are kind of odd.
Since it’s not plausible to see the the correlation between these ISRPMs and the pathogen disgust scale as evidence that differences in disgust sensitives explain variance in fear of falling down elevator shafts, of getting impaled by a broken-off aileron from an exploding DC-10, of having one’s car appropriated by a gun-wielding meth-infused maniac, or of seeing a drowned toddler floating in swimming pool, we shouldn’t take the correlation between the vaccine ISRPM and the pathogen disgust scale as evidence that differences in people’s disgust sensitivities explain variance in perceptions of vaccine risks either.
In an earlier post I showed that this random assortment of ISRPMs form a scale, which I proposed to call the “scaredy-cat” or SCAT index. The SCAT index measures a random-ass (sorry for technical jargon ) sensibility to worry about things generally.
That makes SCAT a nice validator or test index. If anyone asserts that something explains variance in a risk perception, it better explain variance in that risk perception better than SCAT or else we’ll have no more reason to believe that the thing in question explains variance than that nothing in particular besides an undifferentiated propensity to worry does.
Well, when SCAT goes head to head with disgust, it blows it away –on both vaccine risk perceptions and gentically modified food risk eprceptions.
And guess what? Its effect size (measured in terms of respective squared semi-partial correlations; see Cohen et al. 2003, pp. 72-74) is 4x as big as the effect size of the disgust scale when the two are treated as predictors GM food risk perceptions.
That’s strong evidence that neither of these risk perceptions are meaningfully explained in any meaningful way by disgust.
There's at least one very well done & interesting empirical study finding a correlation between vaccine & GM food attitudes & disgust sensibilities (Clifford & Wendell 2015).
But to conclude that disgust “explains” variance in a risk perception, one has to show more than that the risk perception in question correlates with disgust. One has to show that it correlates with disgust (validly measured) more powerfully than do risk perceptions that clearly have zilch to do with disgust.
Based on this evidence and that featured in my earlier post, I'm now of the view that that can’t be done in the case of vaccine and GM food risk perceptions.
Cohen, J., Cohen, P., West, S.G. & Aiken, L.S. Applied Multiple Regression/Correlation Analysis for the Behavioral Sciences (L. Erlbaum Associates, Mahwah, N.J., 2003).
Clifford, S., & Wendell, D. G. (2015). How Disgust Influences Health Purity Attitudes. Political Behavior, 1-24. doi: 10.1007/s11109-015-9310-z