His article in Sci-Am is worth a read.

Shermer begins with saying the insanity taking place on college campuses can be laid at the feet of having no other ideologies to act as a reality balance. Locked in an echo chamber, it’s a race to the extremes – kind of like a primary race. 

Then Shermer lays out that bias affects not only the descriptive terms used during studies (conservative values as indicators of mental disorders), but in how the data is interpreted. 

RTWT