One of the defining criteria for Asperger's is the presence of the special interest.
I'm going to write this post like a question and answer page to help me stay on topic. Once again, remember that generalizations are based on my experience and may differ from one aspie to the next.
Is it Forever? Usually no, but it seems to be the case that some special interests will last a lifetime (or in my case, at least 35 years - the length of time (so far) of my "love affair" with Dr Who). Lifelong special interests will ebb and flow depending upon other factors, such as availability of new material and other concurrent interests. Sometimes they're quite subdued but they're always there.
Is it only one? No - There are definitely multiple special interests running throughout an apsie's life, but they usually concentrate on one or two at a time. Eventually life-long interests fade to the background to such an extent that the aspie will be able to pick up another special interest without entirely dropping the first.
What happens when a Short-Term Special Interest Ends? As a general rule, they end quickly. One day the special interest is there, the next it isn't and the aspie is left with all kinds of memorabilia which no longer fits their special interest.
At first, the aspie won't want to get rid of that stuff, after all, it may have cost a bit, or still have some significance but eventually, as the clutter gets too much they may reach a snap decision to get rid of it all.
About 5 years ago, I went through a cocktails making phase which lasted a couple of years. I ended up with a lot of bottles of various substances, many of which are unopened. I've still got a lot them at home because I find it difficult to just throw them out. Eventually I'll bite the bullet though.
(For a funny story about how I disposed of one, click here )
Is there a medical reason for the Special Interest It seems so, there's research suggesting that aspie's are only able to concentrate on one thing at at time. This is normally for day-to-day processing but it seems to me that the whole special interest thing is a larger version of "one thing at a time).
What can I do as a Parent if I don't like the Special Interest? Not much I'm afraid, just hope it will go away. If you nag about it, you're more likely to reinforce it or provoke other negative things (extra collecting, for instance).
When I was in 6th Grade, I was always borrowing Dr Who novelizations from the school library. The librarian and teachers got concerned about "formula fiction" and forbade me to borrow them anymore. This got me started on purchasing and collecting them instead. I now have hundreds (and I still buy and read them).
Occasionally a special interest will be obviously quite unhealthy, collecting scabs for instance. No.. I never did this but I know some kids who did. One in particular had a whole lunchbox full of them - yuck!
If the special interest is unhealthy, then as a parent, you shouldn't register distaste etc.. Just try to be neutral and disinterested. If possible, find something else and try to get your kids interested in that. Develop a "special interest" of your own and talk about it, get books about it etc... It sometimes rubs off.
Why don't Aspies Realize that I'm not interested? The special interest is all-consuming. Young aspies don't realize that you're not interested - it sounds very interesting to them. Older aspies do realize and often they'll try not to discuss them. The trouble is, that aspies tend to think out loud and often talk to themselves, particularly about their interests.
They will often talk incessantly about things knowing that the other person has no interest. This will either be because they want to hear about it - even if it is only their own words out loud or because they feel that it's important for other people to know about the subject.
I frequently tell my poor wife about what's coming up in the movies, who a particular writer or director is and where they get their inspiration. She's not interested and will often talk over me. This makes me annoyed and resentful but I do understand that she's long-suffering and has little patience. Luckily for me, aspies tend to attract aspie friends or friends with similar interests.
Why won't my Aspie listen to me? I listen to them... Aspies have a lot of trouble listening to things outside their special interests. If I'm at a party and someone starts discussing football, I feel left out and tend to walk away. If my wife starts talking about renovating, moving house or real estate, I also tend to switch off. At work, I'm fine while looking at most of our systems but I can't look at our financial systems without feeling out of depth because of the words.
Sorry, I don't really have an answer for you. The best I can suggest is that if you really need to discuss an off-topic idea with an aspie, give it to them in simple terms and preferably in writing. Give them a chance to digest it (and make sure they have a deadline).
If you have to be verbal, make sure it's "planned" - ie: that the aspie knows the topic will be discussed and that the area is generally quiet and free from distractions. Good luck...
What Can Parents Do? First of all, learn to recognize a change in special interest when it hits and use these interests to your advantage.
For example; If you child develops an interest in spiders and insects, then you can do the following;
Math Homework to: "If five flies were flying and two got caught in a web, how many flies would be left"
English Homework: Use sentences like: "The Beetle WENT up the tree" - then get the child to read/spell certain words - That sentence had four of Kaelan's sight-words in it.
There's plenty more examples, but I wont waste space since I think I've got my point across.
What you need to teach your Children Above all, try to teach your children;
"not everyone likes transformers" (or whatever the interest is)
How to read signs that people aren't interested. - Rolling or rubbing of eyes - Glancing away at other conversations, their watch etc. - Going back to pre-conversation activities - newspaper etc. - Shifting/Shuffling of feet - Disinterest key words "well, I'm happy for you" etc.. - Statements of disinterest "well, I never got into that"
How to give people a chance to change the topic during conversation if you notice that they're bored - "Well, enough about me, what have you been up to?" - "Anyway, enough about frogs, what do you do in your spare time?" - "damn.. it's warm in here, what about the weather* isn't it crazy"
*assuming that weather ISN'T a special interest.
What can spouses do? Put up with it mainly I guess... (sorry)
One thing my wife does to me, when I go out with a group is say "you're not allowed to talk about computers,religion or movies". It never works but it does remind me that I need to steer the subjects a bit to make sure everyone feels included. Religion, by the way, isn't a special interest of mine, but is an interest of a good friend.
Giving an aspie a rule sometimes helps in a big way.
Sometimes when the conversation stays too long on a special interest, my wife will give me a certain look, or signal. This is usually enough to get me to start steering the conversation away.