Quick quiz: All children adore playing in sand, and all kids want to swing as high as the swings will go, right? You may be surprised to learn that some kids actually find the feeling of sand in their fists or water over their bodies disconcerting or unpleasant, and are uncomfortable with the sensation of being "out in the air" on a swing. Four-year-old Matty, who's doing great socially in his preK class, gives his teacher pause when he avoids activities like digging in sand or working at the water table. "He's also uncomfortable swinging on swings and engaging in some other forms of outdoor play," says his mom, Laura, who's puzzled by her active, bright son's squeamishness about activities she'd always figured were kids' favorites.

Over-reactive Kids
There's nothing wrong with Matty and other such children; they're simply more sensitive than their peers to certain textures or sensations. There is great variation in the way children react to touch, sound, and the other sensory information that comes at them constantly, from overreaction on one side of the spectrum, to under-reaction on the other. Let's look at overreaction, to touch in particular. Some kids enjoy all kinds of touch — they sift sand through their hands, squish mud, plunge their fingers into finger paints, and mold clay. Other children find the very feel of those substances unpleasant.

This reactivity often reaches its height in the preschool years. It makes sense: Preschool is a time when children are exposed to, and expected to get involved with, all kinds of activities that involve light touch, such as finger painting and sculpting with clay. Also, in preschool settings, children interact in groups, allowing a much greater likelihood of someone bumping or rubbing up against them in line or in a circle.

Any child can display sensitivity to anything along each sensory pathway, from touch to sound to movement. Some children find high-frequency sounds like opera singing bothersome. Others can’t tolerate low-frequency sounds like the vacuum or the boiler in the school basement.

The level of light can also bother some children. Some find bright light, even sunlight, difficult to tolerate and do better with subdued lighting. Sudden movement in space can be overwhelming for some children. While some kids crave the experience of swinging, others can be very upset by this kind of movement. Some children get upset from the smell of perfumes or flowers, while others love them. Some children are finicky eaters because they are very sensitive to the smell or the texture of food.

While the reactivity itself is not an issue, the behavior it may elicit can be. If a child happens to be very sensitive to touch, and is bumped into during circle time at school, he may have tantrums or become irritable and withdrawn. He may even express his discomfort through aggression toward others. A child who doesn't enjoy these activities will often appear to the teacher or parent to have a major problem. However, the challenge may be quite a small one which can be easily worked around.

Under-reactive Kids
The opposite tendency, under-reaction, is also something to watch out for. In these children, some sensations barely register. As a result, they'll seek out those sensations, as if trying to get more bang for their sensory buck. A child who's under-reactive to touch may want to bang into everything, and everyone. The one who's under-reactive to sound may seek out or create loud noises. A child may be running around all the time to create movement.

As with the over-sensitive child, the under-sensitive one may end up looking like he has a behavior problem when he gets to preschool. Why? His search for greater sensation may manifest itself as impulsion or aggression. So what starts as a small difference becomes a big problem.

How to Help
The most critical aspect of helping children who are either under- or over-reactive to sensory experiences is recognizing their differences. Then we can create environments that will be helpful and adaptive rather than jarring or upsetting. If we don't work around these children's differences, a child who is sensitive in one way or another may begin pulling away, or shutting down and withdrawing. Here are some ways both parents and teachers can work with these children (see also my book, Building Healthy Minds):

• If the child is oversensitive to touch, introduce firm pressure, since it seems that light touch is what these children are sensitive to. Then, gradually combine light touch with firm pressure.
  
   
• If the child is oversensitive to sound, help protect him from high-pitched noises. Then, gradually expose him to a greater range of sound, over a long period of time, with a lot of comfort and careful regulation. The same gradual approach goes for movement, light, and smell.
  
   
• If the child is under-reactive and craving more sensation, you can provide what I call modulation and regulation games. The idea is to teach such a child how to interact with his world gradually — moving from super fast to fast, from making loud sounds to softer sounds to very soft sounds. This allows the child to feel he controls the level, and gets what he wants, while he is adapting.