A recent Gallup survey is making the rounds, lately. It has been interpreted by extremely stupid people to state that Alaska is the happiest state in the USA. Even Gallup doesn't go so far to make such a claim, but that never stops extremely stupid people from being extremely stupid. The survey actually bills itself as a "wellbeing" survey. Gallup does give some explanation how they come up with their numbers. One version of their results that has come up a great deal lately talks about just the ranks and presents a map in quintiles. One such example can be found at livescience. If you want, you can go over there and look at their map or look at the first map below. It represents the quintiles in approximately same colors. (If you mouseover the map, you'll get more information by state.)
This map is an excellent example of how data presentation choices can be fraudulent without being fraudulent, how to lie without lying. Honest people use quintiles, quartiles, percentiles, and other such non-parametric numbers to represent either data that has a long, uneven, and strung-out range (like achievement test scores), or to group a different set of data to show how it is distributed (like wealth per quintile). It just so happens that you can look a the wellbeing index scores for yourself. Notice that the data is not the strung-out and scattered. In fact, it is very densely-packed. It also is not linked to some other unevenly-distributed data.
The wellbeing index is actually very densely packed. On a 0-100 scale, the lowest state's index is 59. The highest is 64.7. Think about that, on a one hundred point scale the distance from the worst to the best is 5.7 points! Now look at that first map, again. Is a difference of less than 6% worth that much a visual difference?
How else to represent the difference so people can get an idea of reality instead of a visual lie that technically represents the actual numbers? The second, or "squashed scale" map does that. The "worst color" (light gray) is matched to an index of 59. The "best color" is matched to 64.7. The range between is then evenly filled in among the five color points. Look different? It does. Yes, there is some rough correspondence between the liar's map that comes from Gallup and the (somewhat) more truthful map I created. Look closer: California and Texas are visibly different on the liar's map. Not so much on this one. North and South Carolina are in different quintiles, but their actual scores are very close to each other, which this map actually shows.
But I'm not finished. You see a third map. This is a map where the "worst color" corresponds to an index of 50 and the "best color" corresponds to an index of 100. Thus, changes in color correspond (by half) to actual differences in the index. Having a hard time telling the states apart? That is because the differences among them in this index really are quite small--total range is 5.7 points out of 100. This map shows you what that looks like (actually, it exaggerates the difference by double!).
So, why does Gallup do this, and why do people so stupidly and eagerly swallow such dishonest representation of data? First, explaining Gallup. I don't work there, so this is speculation, but Gallup makes its money off political turmoil, not general popular contentment. Anything they publish that will stir the pot will inspire more surveys that they can sell. Likewise, presenting things in extreme (and dishonest) ways ensures that there will be more arguments, leading to more survey commissions, leading to more dishonest data presentation, leading to more arguments. It's a lucrative circle for Gallup.
But why do people so eagerly devour such steaming dog turds of quasi-information? First, they're simple. People like very stark, very simple things to natter on about with each other. People do not like complex and shaded descriptions. They want things to be very neatly pigeonholed, and this comforts them. In addition, people with dirty agendas want things to presented as rigidly and extremely as possible to the public, all the better to sound the panic alarm and drum the masses into obedience. Finally, we are taught that only rigid and extreme answers can be "true". We are indoctrinated to be mental weaklings, to always see the world as "good" and "evil" with nothing in between. We are taught that someone who is able to see gradual differences is a "fence-sitter" or "spineless". We are told that only extremism is good--although it's only actually extremism when it's someone you don't like doing it.