A key trait and symptom of autism is the avoidance of eye contact, a behavior evident from infancy. The neurological origins of this tendency have been a subject of extensive debate and research, revealing various factors.
While making eye contact is an instinctive and natural inclination for most people, it creates considerable emotional and physical discomfort in the autistic. This discomfort can include increased blood pressure, mental confusion and anxiety, and even physical illness. Forcing children with autism to make eye contact creates significant anxiety.
The autistic experience the world with heightened sensitivity, perceiving sights, sounds, smells, and sensations more intensely. Maintaining eye contact can be overwhelming, creating a sensory overload, and requiring them to adopt avoidance techniques. One person with autism said making direct eye contact is akin to staring at a bright light, and is painful.
Avoiding eye contact not only filters visual information but also allows the autistic to focus on verbal communication. Unlike neurotypical individuals who seamlessly integrate spoken words and facial expressions, many with autism find the cognitive load of processing both simultaneously too intense. They must look away to fully process words and think clearly.
For most people, looking into someone's eyes is a natural and subconscious means of gaining information integral to social interactions. However, for those with autism, eye contact is unnatural and does not align with how they seek social information. The eyes hold no special significance for the autistic. Studies on young children with autism indicate an indifference to gazing into the eyes, the children not focusing on the eyes of people even in videos.
Medical and behavior science research conducted at Yale University and the University of London indicates that the brains of the autistic function and process information differently from neurotypical brains. Eye contact activates social-related parts of the brains of most people, but not in the brains of the autistic.
Note that eye contact as the social norm is not universal. In some cultures, such as in Japan and Mexico, direct eye contact is considered impolite. This highlights the importance of cultural context in understanding and interpreting social behaviors.
Many sources including this one, https://www.lifesize.com/blog/speaking-without-words/#:~:text=There%20have%20been%20a%20number,of%20all%20communication%20is%20nonverbal. claim that the vast majority of information is conveyed non-verbally.
I understand what you are saying about overstimulation or flooding which results when the verbal and non-verbal information is combined, but doesn't the avoidance of eye-contact indicate that a person with a significant degree of autism will miss vast amounts of information in face-to-face communication?