The Journal didn't delve into it, but another major source of eating preferences/disorders (the line between them is fuzzy) is something called sensory processing disorder; this is a neurological problem that causes sufferers to react inappropriately to sensory stimuli: a noise, someone touching them, the feeling of something on their skin. Or in their mouths. Many people who suffer from sensory processing disorder have trouble with certain textures (lumpy, slimy, gooey), or with foods of certain colors (green is typically much hated; white, brown, and yellow foods better tolerated).
Whatever the cause, it's clear that adult picky eaters are pretty much pariahs. And they take a lot of abuse. And they can't help being the way they are, because no one wants to live like this. This My Life in Food episode delves more deeply (and rather heartbreakingly) into the issue.