So here's what got me thinking about this

I was reading this paper about a sociological study about morality and political ideology and what struck me was this paragraph:

Figure 8

"Previous research has shown that liberals are less disgust-sensitive than conservatives (Inbar et. al., 2009). The low level of disgust sensitivity found in libertarians could help explain why they disagree with conservatives on so many social issues, particularly those related to sexuality (e.g. MFQ – Purity in Study 1). Libertarians may not experience the flash of revulsion that drives moral condemnation in many cases of victimless offenses (Haidt, Koller, & Dias, 1993)."

The reference to "flash of revulsion" sounds physiological, and makes me wonder if there is some sort of biological mechanism here - sort of a nice way of saying that some people just can't help but try to impose their way of life upon you any more than they can help their skin pigmentation or gender.

I'm wondering then, if bigotry is biological, what could be the purpose and advantage to it since afaict it is simply an irrational belief in demonstrable falsehoods which I would assume to be a distinct disadvantage. 

More importantly, if it's biological in origin should their mental handicap qualify them for protection under the ADA?