How do people with ASD really feel about novelty?

A recent conversation I had at a comic convention with a man on the spectrum made me wonder if the nonautistic world has misunderstood how people with ASD feel about novelty.

People with ASD repeat gestures, quote lines from TV shows, and get upset by changes of plans they were not warned about in advance.  Some of these behaviors aren't unique to ASD, of course.  People with sensory processing disorders also dislike new places or sudden changes in plans, generally because these generally involve large amounts of stressful sensory input.  (People on the spectrum seem to  dislike changes for similar reasons). The reasons for what diagnosticians call "rigidity" and "insistence on sameness" probably differ depending on the behavior and the situation--e.g., a child with difficulty generating spontaneous language might use quotations to communicate, whereas they might rock to soothe themselves or flick things in front of their eyes because they enjoy the sensation.  What all these behaviors have in common, though, is a degree of repetition that most NTs would find stifling, and an avoidance of new stimuli that NTs typically seek out.  Not surprisingly, it's generally assumed that ASD people do not like novelty.  Unfortunately, this has also contributed to the idea--patently false--that they lack creativity.

Those of us without autism generally learn to see beyond such stereotypes by getting to know people on the spectrum.  The person on the spectrum I know best, my brother, does not like changes of plans, new places, new foods, or new activities, even if he intellectually believes they will improve his situation.  They tend to make him feel anxious.  He has packed the same lunch for school for over a year without getting bored (I would last, at best, a week).  My experiences with him gave me little reason to question my assumptions about novelty and ASD.

I recently went to a comic convention, which hosts not only comic book artists and sellers but a broad range of fantasy and science fiction artists.  While I was standing at a booth talking to one of the artists for a card game I play, Magic, a young man also standing there started talking to me.  Not stopping to introduce himself, ask my name or engage in any of the usual pleasantries, he asked if I knew about a certain aspect of the game.

Brief digression: In Magic, you pretend to be an all-powerful wizard fighting an equally mighty rival.  You cast spells and summon creatures to attack your opponents.  The cards have abilities with consistent names, or "keywords," that describe what these cards do in the game.  One such keyword is landwalk, meaning that if your opponent controls a certain kind of terrain, they can't block your creature (this is a good thing).  There happen to be several different types of terrain in the game, and cards with landwalk don't target all of them equally.  In particular, "plainswalk"--which requires your opponent to control a terrain called a plains--is incredibly uncommon.

Specifically, this man told me, there were only 5 cards with this keyword in the entire game.  In an enthusiastic, yet still somehow monotone, way, he told me how he had worked hard and made a lot of trades to collect each of these cards.  He proudly showed me one of them.

Perhaps millions of different Magic cards have been printed.  The fact that only 5 of this kind existed clearly appealed to him, and he excitedly repeated this fact several times.  Rather than avoiding such a novel thing, this young man who talked like a stereotype of a person with Aspergers had gotten obsessed over it.

The conversation reminded me of something else--ASD people periodically change their special interests, adding new ones and dropping old ones.  For example, I read recently that younger children are more likely to focus on objects, but switch to interests in topics as they get older and more intellectually mature.  In other words, a preschooler might be obsessed with toilets or washing machines, while a school age child might have a special interest in dinosaurs.  Eventually, they seem to feel they've gotten everything they can out of one interest, and voluntarily seek out novelty--a new interest.

Clearly, then, the NT world has oversimplified--ASD people do not necessarily dislike all novelty.  However, they do seem to deal with it differently.  So, readers, especially if you have ASD yourself: what do you think determines whether a person on the spectrum seeks new things or avoids them?  Is it the type of topic or activity--maybe activities that involve seeking out information or collecting things are the easiest to engage in?  Is it the control one has over the situation--in the same way loud noises are easier to tolerate if one makes them oneself, maybe new things are more enjoyable if one determines what one experiences and when? Are new ideas more pleasant than new sensory or social experiences? What about the amount of time spent on the old interests--does it take ASD people longer than most to feel like they need new stimulation?  At one point is an old special interest exhausted?  How closely does a new interest need to relate to the old interest(s)? 

People are starting to come up with explanations of social behavior in ASD that are less dehumanizing and more accurate (e.g., the Intense World theory).  We need something similar for "insistence on sameness."  What do you think a better explanation will look like?