I think this thread has made some very good points regarding the difficulties in categorizing intellectualism vs pseudo-intellectualism. I have found some defining characteristics of pseudo-intellectualism though, but they are guidelines for me rather than hard and fast rules.

If a person is talking about an intellectually heavy topic with disdain for other points of view, exasperation at having to explain it again, and/or an aire of boredom - then it is probably a pseudo-intellectual treatise. For instance, I have a Bachelor of Science degree in physics and mathematics and am a member of Mensa. I have taken some post graduate courses and have a working understanding of quantum mechanics. It's fair to say that I'm pretty versed in the field. Rather than work in my field however, I opted for a different path and became a professional poker player.

In the months and years immediately following 9/11, I got to listen to conversations at the poker table almost daily from conspiracy theorists about how 9/11 was done by our own government. They spoke of the manner in which the buildings fell, spoke of stress points, metal fatigue and melting points. They made all kinds of physics arguments, using bonafide physics terminology and broad statements about how 'obvious' it was. They dismissed any counter arguments, out of hand, regardless of how valid they may have been - but couldn't actually maintain a conversation much beyond the rehearsed reasons they had memorized from an article or news story or whatever sources they were quoting and pretending to be their original thoughts.

Personally, I have no idea whether or not 9/11 was a conspiracy. With my education, the next twenty years and unfettered access to evidence I might be able to form a factual, intelligent opinion. They couldn't - but it didn't stop them from pretending that they could. The greatest evidence that theirs was a pseudo-intellectual argument was the fact that they knew. That, and they treated everyone who didn't agree as a complete idiot.