Home » Sensory Solutions » Sensory‌ ‌Defensiveness‌ ‌in‌ ‌Autism: Signs, Causes, and Types

Sensory‌ ‌Defensiveness‌ ‌in‌ ‌Autism: Signs, Causes, and Types

November 7, 2023

Just imagine walking into a busy cafe, where you’re met with a strong smell of coffee, hot air filling the room, and loud music filling your ears. Just thinking about it may make your anxiety start building up. Welcome to the world of sensory defensiveness, where even the most innocent stimuli will drive children with autism to exaggerated responses.

Sensory defensiveness is a hallmark trait of autism, and it can be hard to deal with – both for children on the spectrum and their families. In this comprehensive guide, we’ll help you manage this condition in your little one so they can experience the beauty of life without feeling threatened.

Sensory‌ ‌Defensiveness‌ ‌in‌ ‌Autism: Signs, Causes, and Types

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Sensory Processing Disorder The Ultimate Guide

What is Sensory Defensiveness?

Sensory defensiveness is part of a sensory modulation disorder that falls under the umbrella of sensory processing disorders (SPD). Sensory defensiveness is a group of symptoms occurring as a result of a defensive or (over) reaction to neutral or even positive stimuli.

More specifically, in 1991, Wilbarger & Wilbarger provided us with one of the earliest explanations: “The tendency to react negatively or with alarm to sensory input that is generally considered harmless or non-irritating is typical of sensory defensiveness. Common symptoms may include oversensitivity to light, unexpected touch, and sudden movement, or overreaction to unstable surfaces, high-frequency noises, excessive noise or visual stimuli, and certain smells.”

The world is an overwhelming place for a child whose senses react this way to everyday or neutral stimuli. Their sensory defensiveness will cause them to react to such input with negative behavior and emotions. They may even avoid daily routines to protect (or defend) themselves, and this could lead to delays in reaching developmental milestones.

Types of Sensory Defensiveness

Sensory defensiveness can be observed in any, or sometimes all, of the sensory systems. The child will try to defend themselves against the offensive (or so perceived) sensory stimulus by avoiding it, minimizing exposure, or displaying certain behaviors or emotions like irritation, frustration, or aggression.

Defensiveness in the following sensory systems is identifiable by the corresponding behavior: auditory defensiveness, visual defensiveness, oral defensiveness, vestibular, gravitational, or postural insecurity, and tactile defensiveness.

Auditory Defensiveness

An extreme sensitivity to sound characterizes auditory defensiveness. The child’s nervous system may interpret sounds as too loud, or the pitch may be intolerable. To deal with the discomfort, the child may act out, try to avoid or minimize the auditory input, hyper-focus on something else, or escape.

The following behaviors may be observed in children with auditory defensiveness:

  • They may show extreme sensitivity to every day sounds like the vacuum cleaner or hairdryer. Often, a child experiencing such sensitivity or defensiveness will cover their ears or appear anxious and tense in a noisy environment.
  • They may not like activities or environments usually loved by kids. Birthday parties, kid-centered restaurants, and indoor playgrounds may be too loud and overwhelming for them.

Visual Defensiveness

It is usually not difficult to spot visual defensiveness in a child; they will squint and get very uncomfortable in bright light, prefer to be indoors when the sun is shining, and get disorientated if an environment is visually overwhelming.

For some kids, visual defensiveness manifests in the following manner:

  • A camera’s flash will leave their eyes watery and sore;
  • They insist on wearing sunglasses whenever they step outside;
  • They may get nauseous looking at vast, moving, bright objects like a roller coaster or merry-go-round;
  • Some of these children actually feel their eyes burn when they have to maintain eye gaze (or contact) — the link between autism and sensory defensiveness may find relevance in such examples, but more on this later.

Oral Defensiveness

In this category, the defensiveness of the olfactory (sense of smell) and gustatory (sense of taste) systems are often included. Some treat oral defensiveness as a separate category. In that case, they focus purely on defensiveness exhibited in reaction to touch of the mouth or anything being put in the mouth, like medication or food.

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In general, children with oral, taste, and smell defensiveness will:

  • have extreme reactions and an aversion to oral hygiene. For some parents, brushing their child’s teeth ends in tears (or worse!) daily;
  • be very particular about food texture, either crunchy or soft and mushy. A mixture of textures is usually not tolerated at all this may be apparent when the child gags when introduced to baby food with lumps or small pieces of vegetables;
  • sensitivities may extend to spiciness and the smell of spices. Usually, bland food is preferred.

Vestibular, Gravitational, or Postural Insecurity

The vestibular system contributes to balance, detects head motion and position, and provides important messages and information to the brain about the location of the body in relation to its surroundings.

A child with vestibular insecurity may:

  • show an adverse reaction to having their head tipped, moved or manipulated (at the dentist or hairdresser)
  • prefer sedentary activities; the child may not enjoy bike riding or swinging as their feet are off the ground, and their balance issues may create anxiety

Tactile Defensiveness

When referring to sensory defensiveness, tactile defensiveness is probably the most well-known and most studied area of sensory defensiveness. Dr. Jean Ayers was an occupational therapist who first identified tactile defensiveness in children in 1964.

A child with tactile defensiveness will over-respond to touch, or as Dr. Ayers explained, they may have a negative reaction or avoidance of non-noxious tactile stimuli.

Tactile defensiveness may manifest in some of these behaviors:

  • Avoidance of light touch, but actually seeking out deep touch
  • May show a strong preference for certain types of clothing and will be bothered by clothing labels, shoes, and many other things that other children don’t seem to notice
  • Does not like to get hands dirty or the feel of specific play materials like putty
  • May avoid walking on surfaces like grass or a specific type of carpet

Defensiveness in any or all of these sensory areas may lead to behavior of avoidance or acting out. Sensory defensiveness is misunderstood, and because it is not recognized as an official medical diagnosis, these children are often described as out of control — when their brain tells them their world is out of control, they’re merely reacting to that message.

Sensory Defensiveness and Autism

Many published studies have confirmed the high percentage of autistic children with sensory difficulties and disorders. According to a study conducted by  Tomchek and Dunn in 2007, 95% of the sample of children with autism spectrum disorder (ASD) showed some degree of sensory processing difficulty.

In the DSM-5 criteria for autism spectrum disorders, atypical sensory behaviors are listed as a possible symptom of restricted, repetitive behavior, interests, or activities.

Taking the odds into consideration, your autistic child is very likely to have sensory difficulties or sensitivities, and this may well be sensory defensiveness. It is very important to remember this, as the knowledge may prepare parents for situations that could potentially overwhelm their children with autism.

A study by Spira and Kupietsky looked at oral defensiveness in children with dysfunctional sensory regulation. The principles discussed were applied to a dentist appointment. Going to the dentist is not a treat for many or any of us, but the details of the study give an idea of just how traumatic it must be for a child with sensory defensiveness.

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Sensory Processing Disorder The Ultimate Guide

From the authors’ suggestions of how to make the child comfortable, the following becomes apparent:

  • The child will be entering a place with bright lights, many unfamiliar people, noise from dental apparatus, and various chemical smells. In this regard, suggestions for keeping the environment similar and offering choices are discussed.
  • The child will touch their face and mouth, possibly alerting their tactile and oral defensiveness. They may also have to tip their head back and sit on a reclining chair with their feet off the ground — which is tough on vestibular insecurity.
  • Most traumatically, a loud suction machine will be inserted in their mouth, possibly activating not only oral but also auditory defensiveness.

Imagine your autistic child dealing with the social challenges of visiting the dentist, and then add all these sensory defensiveness challenges to the appointment. No wonder the authors say the dental environment may be a “source of great difficulty for the child and parents.” Their suggestions of making the child comfortable rely on the pediatric dentist being educated about the challenges with oral defensiveness.

In a presentation, Supporting Nervous System Function Through Sensory Intervention and Adaptation for the Autism Parenting Summit, author and behavioral therapist Rebecca Duvall Scott and occupational therapist Hannah Ragan shared some advice for parents dealing with sensory difficulties.

Rebecca detailed the story of her son’s journey with sensory processing disorder and, along with Hannah, shared many practical tips to help children with sensory difficulties thrive.

Some of these suggestions include:

  • A sensory diet: Sometimes, a child must eliminate gluten and dairy. The child may also need to be tested for deficiencies, and their diet may need to be supplemented to enable optimum functioning of the nervous system.
  • Occupational therapy and speech therapy: Work with a team that understands your child’s condition and specific sensory difficulties
  • Environmental adaptations are often needed to make certain experiences sensory-friendly: Practical examples like taking noise-cancelling headphones to loud places or providing deep pressure with weighted blankets during times of stress are discussed.
  • Above all, parents should be aware of their child’s triggers: They can then make the child aware of these and help them become sensory-smart. The presenters make a great case for a child who is aware of (and understands) their own sensory needs. Such children can advocate for themselves, control their environment better, and ultimately make better decisions (about things like future careers, etc.) as they recognize their strengths and sensory limitations.

Rebecca and Hannah wrote a book with treatment strategies and insights for parents helping their kids deal with sensory differences: Sensational Kids, Sensational Families: Hope for Sensory Processing Differences.

Potential Causes of Sensory Defensiveness in Autism

To effectively support individuals with autism sensory defensiveness, it’s essential to understand the potential underlying causes. While each case is unique, some common factors include sensory processing differences, sensory integration challenges, and anxiety.

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Sensory Processing Differences

According to a research article published in 2022, individuals with autism often have atypical sensory processing, leading to heightened sensitivities. Understanding these differences is key to providing appropriate support.

Sensory Integration Challenges

Sensory integration refers to the brain’s ability to process and make sense of sensory information. For those with sensory defensiveness, this process may be disrupted, leading to heightened responses.


Sensory defensiveness can trigger anxiety and feelings of being overwhelmed. It’s important to address these emotional aspects alongside sensory challenges.


Research is only starting to change people’s perceptions about sensory difficulties. For too long, many in the medical community refused to acknowledge SPD and other sensory challenges. For children with autism — who may already be fighting an uphill battle dealing with daily social and communication challenges — sensory defensiveness makes the world an overwhelming place.

Parents who educate themselves, advocate for their children, and who try to make their child’s environment just a little less scary and overwhelming are making a huge difference. Your autistic child with sensory defensiveness is probably really tired of fighting a battle the world is oblivious to.


Q: Is sensory defensiveness exclusive to autism?

A: Sensory defensiveness is commonly associated with autism, but it can also occur in individuals without an autism diagnosis However, it’s more prevalent in the autism community due to sensory processing differences.

Q: Can sensory defensiveness change over time?

A: Yes, sensory defensiveness can evolve over time. Some individuals may become more or less sensitive as they age or with the help of therapy.

Q: Are there medications for sensory defensiveness?

A: Medications are not typically used to treat sensory defensiveness itself. However, medications may be prescribed to manage potential causes and co-occurring conditions such as anxiety or ADHD.

Q: How can parents and caregivers support a child with sensory defensiveness?

A: Parents and caregivers can provide support by learning about their child’s specific sensitivities, seeking professional guidance, and creating sensory-friendly environments at home.

Q: Can sensory defensiveness be overcome?

A: While sensory defensiveness may not be eliminated, individuals can learn to manage and cope with their sensitivities through various therapies and strategies.

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