My "Happy Society" class has conducted a project to sign up the entire Centre College community as organ donors. We have had excellent success with the faculty, pretty good success with students, but only so-so with the blue-collar staff.
A couple of the latter said they would not sign up as organ donors because they "came in with all their organs, and they plan to go out with them."
I have a hypothesis about why this is so, which I don't have enough data to test. Jonathan Haidt, in The Righteous Mind, argues that all kinds of people tend to have immediate emotional reactions to moral questions. Educated people, though, have trained themselves to only accept judgments that serve to prevent harm and advance care, or prevent inequality and advance fairness. But most people also have an emotional commitment to liberty, sanctity, loyalty, and purity. If they are not trained in Enlightenment theories, most people will go with their first emotional reactions.
My hypothesis is that when some people imagine their organs going in to other people react with disgust at the impurity of it, the pollution of their identity that would result.