Folk Epistemology: Granularity

Example from here, via.

The last point is not a trivial one, since although our country is only about 13 percent black, according to a 2001 Gallup survey most people thought the figure was 33 percent, with the average non-white putting it at 40 percent.¹⁰⁴ This was roughly confirmed by the GSS respondents in 2000, who also believed that nearly 18 percent of Americans were Jewish, a figure more than eight times too large.¹⁰⁵ A very recent 2012 survey found that Americans believe Protestants outnumber Jews in this country by only 2.5 to 1, when the actual ratio is ten times greater.

From the perspective of the average mind, there's often nothing between 0 percent and 33 percent. The other options are 66 percent and 100 percent.
There are more than zero blacks in America, but it's not a majority, so that's 33%.

Essentially this is all confabulation. They have little to no idea what statistics mean, and trying to get quantities out of their fuzzy magnitude estimates is always going to be a pointless exercise in inaccuracy.

The average mind has broad categories. "None," "almost none," "a few," "some," "a bunch," "a whole bunch," and so on, based purely on the emotional experience of what they see in front of them. And why would they bother being more precise? They don't need to take a census, they just need to 'bond' with other average minds by having similar experiences. And maybe sometimes avoid places with "a whole bunch" of blacks.

There's "several times" more Protestants than Jews. (Assuming they even share the surveyor's idea of a "Protestant.") Three is several times, isn't it? If it was 25 times, there would be "almost no" Jews. There's clearly "a whole bunch" of Jews in some places, so that can't be right, can it?

More than half of America can barely grasp what numbers mean when it comes to balancing their chequebook. (Do folk still do that? Did they ever, really?) Why do you think they're going to take the effort to not be 'ignorant' of the correct demographic-statistical ratios?

It's not like they actually can't into numbers at all. Carpentry is not a high-IQ profession. It's just work, an experience the average surveyor could never imagine. However, asking for work from folk who have already been to work and would rather be having dinner is not going to end as the surveyor expects.

This is however a problem when politicians consult the public on things like airplane crashes and terrorism. Emotion drives out reason, even if they were into the work necessary, and you'll get two broad factions: those who say planes "never" crash and those who say 33% of frequent fliers will die in a plane crash. The solution being, predictably enough, don't do democracy.