Okay-- "tomorrow" has arrived & it is therefore time for me to disclose the "answers" to the MAPKIA episode 2 contest. And to figure out which of the 10^3s entrants has won by making the "correct" predictions based on "cogent" hypotheses.

Just to briefly recap, the contest involved the "interpretive communities" (IC) alternative to the "cultural worldviews" (CW) strategy for measuring risk predispositions. Whereas the CW strategy uses cultural outlook scales to measure these these dispositions, IC "backs" the dispositons "out" of individuals' risk perceptions.

Applying factor analysis to a bunch of risk perceptions, I identified two orthognal risk-perception dimensions, which I identified as the "public safety risk" disposition and "social deviancy risk" disposition.

Treated as scales, the two factors measure how disposed to see the individual risks that form their respective indicators as "high" or "low." Because the factors into four "interpretive communities": ICs--IC-α (“high public-safety” concern, “low social-deviancy”); IC-β (“high public-safety,” “low social-deviancy); IC-γ (“low public-safety,” “low public-safety”); and IC-δ (“low public-safety,” “high social-deviancy”).

The MAPKIA questions were ...

(1) How do IC-αs, IC-βs, IC-γs and IC-δs feel about the risks of childhood vaccinations? Which risk-perception dimension--public-safety or social-deviancy--captures variation in perception of that risk? (2) Hey--where is the Tea Party?! Are its members IC-αs, IC-βs, IC-γs, or IC-δs?!

Now the "answers"

1. Neither risk-perception dimension explains a meaningful amount of variance in vaccine risk perceptions because none of the groups culturally polarized on "public safety" and "social deviancy" risks is particularly worried about vaccines!

I measured vaccine risk perceptions with 14 risk perception items (e.g., "In your opinion, how much risk does obtaining generally recommended childhood vaccinations pose to the children being vaccinated? [0-7, "no risk at all"-"Very high risk"] "Childhood vaccines are not tested enough for safety" [0-6, "strongly disagree"-"strongly agree"; "I am confindent in the judgment of the public health officials who are responsible for idenitfying generally recommended childhood vaccines" [same]).

The items formed a highly reliable (Cronbach's α = 0.94) unidimensional scale that can be viewed as measuring how risky members of the sample perceive vaccines to be.

For now I'm going to use the vaccine-risk perception scores of an N = 750 subsample, the members of which formed the "control" group in an experiment that tested how exposure to information of certain kinds of information affected vaccine risk perceptions (more--much much much more -- on that in a future post!). Here is how the vaccine-risk perceptions of those individuals "registered" on the public safety and social deviancy scales (using locally weighted regression to observe the "raw data"):

There's a tiny bit of "action" here, sure. But it's clear that vaccine-risk perceptions are not generating nearly the sort of variation that the indicator risks for each factor are generating. Vaccine risks wouldn't come close to loading on either of the factors to a degree that warrants the inference that variance is being caused by the underlying latent disposition -- the interpretation that one can give to the relationship between the factor and its various risk-perception indicators.

But, yes, there is a bit of variance--indeed, a "statistically significant" amount being picked up by each scale.

But "statistical significance" and "practical significance" are very different things. a proposition often obsured by researchers who merely report correlations or regression coefficients along with their "p-values" without any effort to make the practical effect of those relationships comprehensible.

So I'll show you what the practical significance is of the variance in vaccine-risk perceptions "explained" by these two otherwise very potent risk predispositions.

For purposes of illustration, I've modeled the predicted responses of typical (i.e., +1 or -1 SD as appropriate on the relevant scales) IC-αs, IC-βs, IC-γs, and IC-δs to one of the items from the vaccine-risk perception scale (I could pick any one of the items & illustrate the same thing; the covariance pattern in the responses is comparable for all of them, as reflected in the high reliability of the scale):

The "variance" that's being explained here is the difference between being 75% (+/- 5%, LC = 0.95) and 84% (+/- 3%) likely to agree that vaccine benefits outweigh the risks. Members of any of these groups who "disagree" with this proposition are part of a decided minority.

In other words, vaccine risks do not register as a matter of contention on either of the major dimensions along which risk issues culturally polarize members of our society.

Surprised?

Well, in one sense you shouldn't be. Cultural polarization on risk is not the norm. Most of the time culturally diverse citizens converge on the best available scientific evidence -- here that vaccines are high benefit and low risk -- because the cues and processes orienting members of different groups with respect to what's known by science are pointing in the same direction regardless of which group they belong to.

Conflict occurs when risks or like facts become entangled in antagonistic meanings that effectively transform positions on them into badges of membership in and loyalty to competing groups. That's happened for climate change, for gun control, for nuclear power, for drug legalization, for teaching highschool students about birth control, etc.

But again, this hasn't happened for childhood vaccines.

Still I can understand why this might be surprising news. It's not the impression one would get when one "reads the newspaper" -- unless one's paper of choice were the CDC's Weekly Mortality and Morbidity Reports, which every September for at least a decace have been announcing things like "Nation's Childhood Immunization Rates Remain at or Above Record Levels!, "CDC national survey finds early childhood immunization rates increasing," etc.

That's because vaccination rates for all the major childhood diseases have -- happly!-- been at or above 90% (the target level) for over a decade.

Nevertheless, the media and blogosphere are filled with hyperbolic -- just plain false, really -- assertions of a "declining vaccination rate" being fuled by a "growing crisis of public confidence,” a “growing wave of public resentment and fear,” etc. among parents.

Also false-- at least if one defines "true" as "supported by fact": the completely evidence-free story that "vaccine hesitancy" is meaningfully connected to any recognizable cultural or politcal style in our society.

I've posted this before, but here you go if you are looking for the answer about the correlation between concern about vaccine risks and right-left political outlooks (from the same study as the rest of the data I'm reporting here):

This isn't to say that there aren't people who are anti-vaccine or that they aren't a menace.

It's just to say that they are a decidedly small segment of the population, and whatever unites them, they are outliers within all the familiar recognizable cultural and political groups in our pluralistic society.

That's good news, right?!

So is it good to disseminate empirically uinformed claims that predicatably cause members of the public to underestimate how high vaccination rates genuinely are and how much cultural consensus there truly is in favor of universal vaccination?

I don't think so.

Indeed, more later on the not good things that happen to IC-αs, IC-βs, IC-γs, and IC-δs when empirically uniformed commentators insist that being "anti-vaccine" is akin to being skeptical about evolution and disbelieving climate change (I've already posted data showing that that claim is manifestly contrary to fact, too).

2. The Tea Party-- they are terrified of social deviancy!

I guess I'm becoming obsessed with these guys. They surprise me every time I look at them!

I had come to the conclusion that they really couldn't just be viewed as merely "very conservative," "strong Republicans."

But I still don't quite get who they are.

Well, this bit of exploration convinces me that one thing they aren't is libertarian.

This scatterplot locates self-identified tea party members -- about 20% of the N = 2000 nationally representative sample -- in the "risk predisposition" space defined by the intersection of the "public safety" and "social deviancy" risk predispositions.

No surprise that tea party member score low on the "public safety" scale.

But it turns out they score quite high onthe "social deviance" one! They are pretty worried about legalization of marijuana, legalization of prostitution, and sex ed (all of those things).

Indeed, they are more worried (M = .51, SD = 0.85) than a typical "conservative Republican" (0.33, SD = 0.85).

These are the folks who Rand Paul is counting on? Maybe I don't know really get him either.

Actually, if being in the tea party can be consistent with being pro- Michele Bachmann & pro- Rand Paul, then clearly there's nothing "libertarian" about calling yourself a member of this movement (but if one is measuring the opinion of ordinary folk, there's probably only a tiny correlation between calling oneself "libertarian" and actually being one in any meaningful philosophical sense).

Just for the record, the tea party folks are less worried, too, about "public safety" risks than the averge "conservative Republican" (M = -0.87, SD = 0.79 vs. -0.52, SD = 0.69).

Wow.

Now, who won the contest?

Boy, this is tough.

It's tough because both @Isabel and @FrankL had some good predictions and theories about tea-party members' risk dispositions. Indeed, Isabel pretty much nailed it. @FrankL expected the TP members to be more "anti-deviancy" -- I guess I sort of thought that too, although mainly I'm just perplexed as to what self-identifying with the TP really means.

But I feel that I really can't award the prize to anyone, because no one offered a theoretically cogent prediction about why no one would really be worried about vaccine risks. I think you guys are ignoring the silent denominator!

But both @Isabel and @FrankL deserve recognition & so will get appropriate consolation prizes in the mail!

Oh, and of course, anyone who wants to appeal the expert panel's determination can-- by filing an appropriate grievance in the comments section!