The crucial stress hormone cortisol has long played a role in the ongoing autism conversation. But a new study comes closer to clarifying the biochemical differences between control subjects and those with autistic spectrum disorders.

Cortisol is one of the hormones that regulates our stress levels and helps to determine how we will respond to the unexpected events and sensations that greet us in nearly every situation. A British study of Asperger’s Syndrome children published in the journal of Psychoneuroendocrinology finds that affected subjects have less cortisol in their systems at any given time than their control group peers.  

Stressful circumstances spur the brain to flood the body with cortisol, essentially calming the inherent panic response and allowing for more reasoned behavior. Most people experience an observable surge (nearly 100%) in cortisone levels within 30 minutes of waking in the morning, and this burst of stress control helps the body spring into a state of alertness and prepares it for the inevitable challenges that will color the coming day. As the day continues, levels of cortisol in the body slowly decrease as sleep approaches. But the Asperger children in the study did not experience this morning refresher, even though their initial cortisol levels decreased throughout the day.

This lack of chemical conditioning could explain the difficulty that so many autistic children experience when confronted by uncertainty or a change in their daily routine. One of the best-known autistic stereotypes is that of an individual who must repeatedly perform the same sequence acts at exactly the same time or run the risk of falling into an incoherent fit. The fact that the Asperger’s adolescents in this study did not get the same morning cortisol shot as their peers and that their overall levels were lower throughout the day may very well explain a behavioral trait that applies to nearly all spectrum disorder subjects, no matter how extreme their condition.

So are some Asperger’s symptoms tied to a faulty stress-response system rather than an underlying behavioral problem? Only further studies can tell. For now, researchers and the parents of autistic children may better understand why affected kids stick so stubbornly to their routines. And they may be able to use this knowledge to design a more productive response system of their own. The closer we come to understanding the autistic perspective, the more fully we can engage with those who see the world through its lens.