By Dr Khutso N. Sebetseba — Paediatrician | Pocket Paediatrics with Dr K
-Why Behaviour Often Reflects Overload, Not Defiance
When autism is discussed in everyday conversation, the focus often falls on behaviour.
-Why does the child avoid eye contact?
-Why do they repeat movements?
-Why do they have meltdowns , or struggle in busy classrooms?
But behaviour is rarely the starting point. Autism spectrum disorder (ASD) is fundamentally about how the brain and nervous system process the world. When we understand autism through the lens of nervous system regulation, many behaviours that once seemed puzzling begin to make sense.
Autism in the South African Context
Globally, autism is estimated to affect around 1 in 100 children, making it one of the most common neurodevelopmental conditions worldwide.
In South Africa, however, the true prevalence remains difficult to measure. Local studies have reported rates ranging between 0.08% and 2%, but experts agree that these figures likely underestimate the true number of children on the spectrum due to limited large-scale screening and diagnostic resources.
One estimate suggests that over one million South Africans may be living with autism, highlighting the scale of the condition nationally. Yet many children remain undiagnosed or are identified later than they should be, particularly in communities where access to developmental services is limited.
Understanding autism as a difference in nervous system processing can help both clinicians and families recognise its signs earlier.
A Nervous System That Processes the World Differently
For many autistic individuals, the nervous system responds more intensely to sensory information. Sounds may seem louder. Lights may appear brighter. Clothing textures may feel unbearable. Unexpected changes can provoke distress.
Research shows that up to 90% of autistic individuals experience sensory processing difficulties; meaning everyday environments may feel overwhelming. Imagine trying to concentrate in a classroom where chairs scrape constantly, fluorescent lights flicker, and multiple conversations happen at once. For some children, this is not a mild distraction – it is intense neurological overload.
When sensory input exceeds a child’s ability to regulate it, the nervous system activates the autonomic stress response, sometimes described as fight, flight, or freeze.
This may appear as:
- agitation or distress
- withdrawal or shutdown
- repetitive movements
- covering ears or avoiding eye contact
- attempts to escape the environment
These behaviours are often misunderstood as deliberate misconduct. In reality, they may represent the brain trying to regain regulation and safety. Repetitive movements, like headbanging, rocking, or hand flapping , sometimes called stimming, can help calm the nervous system and restore balance. What looks unusual to others may be a child’s most effective coping strategy.
Meltdown vs Tantrum: A Critical Distinction
One of the most important concepts for parents and teachers to understand is the difference between meltdowns and tantrums. A tantrum is usually goal-directed behaviour – a child protesting to obtain something they want.
A meltdown, however, occurs when the nervous system becomes overwhelmed. During a meltdown, a child may cry, shout, or collapse emotionally because their brain’s regulatory systems have exceeded capacity.
Punishment rarely resolves meltdowns because the child is not choosing the behaviour – their nervous system is reacting to an overwhelming environment or stimulus.. Recognising this difference allows adults to respond with support rather than discipline.
What Paediatricians Often Hear
In the consultation room, families rarely arrive saying their child’s nervous system is dysregulated. Instead, they describe patterns. A child who becomes exhausted after school. Or struggles with noisy classrooms. Or who cannot tolerate certain clothing or food textures. Or becomes deeply distressed when routines change.
Taken individually, these behaviours may seem unrelated. Together, they often reveal how a child’s nervous system processes stimulation. Parents are frequently the first to notice these differences, and their observations are invaluable.
Supporting a Sensitive Nervous System
Understanding autism from a neurological perspective shifts the focus from controlling behaviour to supporting regulation.
Helpful supports may include:
- predictable daily routines
- preparing children for transitions
- access to quiet recovery spaces
- sensory accommodations such as noise-reducing headphones
- visual supports to reduce uncertainty
- time to decompress after demanding environments
Small adjustments in environment can significantly reduce stress and allow children to participate more comfortably in school and social settings.
Seeing Behaviour Through a Different Lens
Autism Awareness Month encourages us not only to recognise autism, but to expand how we understand it. When we see behaviour through the lens of nervous system regulation, many actions that once seemed confusing begin to tell a story.
A child covering their ears may be protecting themselves from sensory overload.
A child leaving a crowded room may be regulating stress.
A child repeating movements may be calming their nervous system.
Seen this way, behaviour is not defiance. It is adaptation. And once we understand that, the goal is no longer to make children behave like everyone else, but to help the world become more navigable for their nervous systems.
Sidebar: Clinical Pearls for Clinicians and Parents
Possible signs of a sensitive nervous system
- Strong reactions to noise, lights, or textures
- Distress when routines change suddenly
- Social exhaustion after busy environments
- Repetitive movements that help self-regulate
- Need for quiet recovery time after stimulation
Recognising these patterns allows adults to respond with understanding rather than punishment.