Some toddlers resist certain textures of food so intensely that mealtimes become a battle. Others cannot walk on grass without distress, or fall apart completely at loud unexpected noises, or conversely seek such intense physical input that they crash into furniture, bounce on every surface, and seem unable to sit still. Some cover their ears at sounds that other children don't notice. Some only want tight hugs or weighted blankets.
These differences in sensory response are real neurological variations, not naughtiness, not manipulation, and not a result of parenting style. Understanding them changes how parents interpret the behaviour and opens up more effective ways of supporting the child.
Healthbooq (healthbooq.com) covers developmental variation across the early years, including content on sensory differences, autism, ADHD, and approaches to supporting neurodivergent children.
What Sensory Processing Involves
The sensory systems we typically think of are the five classic ones: vision, hearing, touch, taste, and smell. But the body also has two less-discussed sensory systems that are particularly relevant in young children.
Proprioception is the sense of where the body is in space, provided by receptors in the muscles, joints, and tendons. It is what allows you to reach for a cup without looking at your arm, or to judge how much force to use when picking something up. Children with low proprioceptive registration often seek intense physical input because their system is not getting adequate feedback from normal movement: they crash into things, squeeze too hard, love rough-and-tumble play.
The vestibular system, located in the inner ear, processes movement, balance, and spatial orientation. It tells the brain where the body is in relation to gravity and whether you are moving or still. Children who are vestibularly sensitive may be distressed by swings, slides, and any activity that involves the head moving through space. Children who are vestibular-seeking may spin and rock constantly and tolerate fast movement that would make most children anxious.
Most children have some variation in their sensory thresholds. Toddlerhood amplifies this because the nervous system is still developing and the child has not yet developed the coping strategies and self-regulation skills that help manage sensory discomfort.
Sensory Seeking and Sensory Avoiding
These are the two broad patterns of sensory difference, and many children show elements of both.
Sensory-seeking children need more input than usual from certain sensory systems to reach a regulated state. They might crave movement, seek out loud noise, love certain textures and put everything in their mouths for much longer than typical, want intense touch like very tight hugs, or seem unable to sit still. This is often misread as defiance or poor impulse control.
Sensory-avoiding children find certain sensory inputs overwhelming where others do not. They may refuse foods on the basis of texture rather than taste, dislike having their hair washed or nails cut, find clothing labels or seams unbearable, avoid crowds or loud environments, or become disproportionately distressed by unexpected sensory experiences. This is often misread as fussiness or anxiety.
These are not moral categories. A child cannot choose their sensory thresholds any more than they can choose their height.
Sensory Differences and Neurodevelopment
Sensory processing differences are very common in children with autism spectrum conditions and ADHD and are now included as part of the diagnostic criteria for autism in current classification systems. This does not mean that every child with sensory differences is autistic, but it does mean that significant sensory differences warrant attention to the broader developmental picture.
Sensory differences also occur in children without any other neurodevelopmental condition. Highly sensitive children, sometimes referred to in the psychological literature as children with high sensory processing sensitivity, represent a genuine neurological variation rather than a disorder. Elaine Aron's research on the highly sensitive person has been influential in describing this profile.
It is worth noting that sensory differences in the absence of other developmental concerns do not constitute a diagnosis of any kind. They are a variation in how a child processes the world.
Supporting a Sensory-Sensitive or Sensory-Seeking Child
For sensory-avoiding children, the most helpful approach is not forcing exposure to the overwhelming input but allowing the child to approach it at their own pace, giving advance warning of sensory experiences ("we're about to go into the loud hall"), and modifying the environment where possible (seamless socks, clothing without scratchy labels, lower volume settings, noise-reducing ear defenders for known trigger situations like fireworks).
For sensory-seeking children, providing legal, appropriate sensory input throughout the day reduces the degree to which the child seeks it in ways that are disruptive or unsafe. A child who needs proprioceptive input can get it through rough-and-tumble play, carrying heavy bags (a physical activity, not actually heavy loads), pushing a loaded trolley, or using play equipment that gives intense physical feedback. A child who seeks oral input can be given safe chewable items. Meeting the need is usually more effective than suppressing it.
When to Seek Assessment
Consider a referral if sensory differences are significantly affecting the child's daily life: refusing enough foods that nutrition is at risk, unable to tolerate necessary care such as hair washing or nail cutting, not able to engage in any social settings due to sensory overwhelm, or causing significant distress to the child on a daily basis.
A paediatric occupational therapist (OT) is the appropriate professional to assess sensory processing differences. OTs can assess which systems are affected, how significantly, and what strategies and environmental modifications would help. In some areas, referral is through the GP; in others, health visitors can refer directly or parents can self-refer to some services.
Sensory integration therapy, a specific occupational therapy approach, has a degree of evidence behind it for children with sensory processing difficulties, though the evidence base is still developing.
Key Takeaways
Sensory processing refers to how the nervous system receives, organises, and responds to sensory input from the environment and from the body. Children vary considerably in their sensory thresholds, and some toddlers are more sensitive or more seeking of sensory input than is typical, which can affect behaviour, feeding, sleep, and social interactions. Sensory differences are common in children with autism and ADHD but also occur independently. Where differences significantly affect daily life, assessment by a paediatric occupational therapist is the appropriate next step.
