When Ian turned 2-1/2, we knew that something wasn’t right. He only said a handful of words. Ian’s trouble with talking and his poor control of his mouth (he couldn’t blow out the candles on his birthday cake) was always the hugest aspect of his disability. Unlike other kids with autism, he never hand flapped or had restricted interests. He was always warm and affectionate. But other hallmarks of autism showed up later. He began reading at age 3. He had unusual fears and OCD-like compulsion. And between 2 and 5, it became obvious that he was super, super sensitive to all sorts of input.

He couldn’t wear denim or long sleeved shirts. His ability to understand language completely disintegrated in a crowded room. In fact, crowded rooms and parties were downright torturous. Bright sunny days, the fuzzy static of a radio, faces that came too close, a scratchy kiss from Pop-Pop, the incense in church, the smell of a hot bowl of oatmeal — led to tears, gags, panic, and hysteria.

Other things he loved too much. One time, he refused to come out of the ball pit in the IKEA playroom. He was completely submerged in the red and blue balls. Just his little feet sticking up. I had to sign all sorts of wavers and then wade into the ball pit to yank him out. Ah, good times.

As Ian’s sensitivities appeared, I had no idea what to do. We hadn’t gotten an autism diagnosis yet, so I read the wrong things and got advice from all the wrong people. Should I force him to get used to these things or should I have pity on the kid? How much should we change our lives to cater to these sensitivity? Should we stop attending parties and extended family dinners? And try explaining to the grandmas why their grandson gagged at the sight of their dinner and why he wouldn’t put on the nice pants for Christmas. Yeah, it didn’t go over very well.

Until last year, the sensitivity aspects of autism wasn’t even a part of the official definition of the disorder, but if you talked to a parent of an autistic kid, you would get an earful. Yet another way that parents were miles ahead of scientists about autism.

Now, one scientist, who is also a parent of autistic child, writes that the super sensitivities of autistic children may be the root of the disorder. Henry Markham believes that autism isn’t due to cognitive deficits. It’s actually the result of a brain that works too well. It takes in too much emotion, memory, and sensation.

IMAGINE BEING BORN into a world of bewildering, inescapable sensory overload, like a visitor from a much darker, calmer, quieter planet. Your mother’s eyes: a strobe light. Your father’s voice: a growling jackhammer. That cute little onesie everyone thinks is so soft? Sandpaper with diamond grit. And what about all that cooing and affection? A barrage of chaotic, indecipherable input, a cacophony of raw, unfilterable data.

Just to survive, you’d need to be excellent at detecting any pattern you could find in the frightful and oppressive noise. To stay sane, you’d have to control as much as possible, developing a rigid focus on detail, routine and repetition. Systems in which specific inputs produce predictable outputs would be far more attractive than human beings, with their mystifying and inconsistent demands and their haphazard behavior.

This sensitivity is the key to other aspects of the autistic disability, according to Markham. The autistic infant shuts down in response to the over-stimulating world. He misses out on the critical stage of language development and is never able to catch up.

The Markhams think that one of the ways to treat autism is to provide super soothing environments to infants who have certain autistic risk factors. To give them another trimester to cook, but outside the womb. Maybe if autistic infants weren’t so traumatized by sensory input, they wouldn’t shut down and refuse to take in language input.

Sensory and language problems have always gone hand-in-hand with my son. Were the sensory problems the root of the language problems? I’m not sure. I know typical kids who have more sensitivities than Ian. Some kids survive on a diet of Cheerios and peanut butter sandwiches. The middle school boys walk down the street in shorts in the dead of winter. And they all talk. But perhaps all those sensitivities packaged up together is too much for some people. Small quirks are not a big deal, but too many and you shut down.

The good news about autism, at least Ian’s variety, is that sensitivity stuff goes away. He blends in just fine in family parties now. He doesn’t wear jeans yet, but he will wear his Christmas finest when required. He doesn’t bolt when taken to a parade with a loud marching band. With his earbuds in his iPod Shuffle, he listens to his custom-made mixes of music for hours.