The information below was taken from: Autism.org.uk.
There are many signs that a child or adult may be autistic. To get an autism diagnosis, a specialist team must agree that a person shows the ‘core characteristics’ of autism. These are lifelong differences in communication, behaviours and interests compared to non-autistic people.
Communication
Autistic people may have different communication styles, skills and preferences to non-autistic people. They may use and understand words, tone of voice and body language, such as gesture and facial expressions, differently.
Some autistic people have intermittent, unreliable, limited or no speech. They may communicate in other ways, for example: in writing or sign language, through gesture or sounds, or by using Augmentative and Alternative Communication (AAC), such as picture cards and/or high-tech devices.
Behaviours and interests
A lot of medical and professional literature refers to these differences as ‘restricted and repetitive behaviours and interests’ (RRBIs). They must be seen as affecting ‘everyday functioning’ for a diagnosis to be made.
But many autistic people see these characteristics as positive and helpful. Some prefer to describe them as ‘stimming’ (stimulatory) or ‘self-regulatory’ behaviours – ways to keep calm and happy.
These include having or showing:
- focused and dedicated interests (such as a very strong passion for a hobby, an entertainment figure or series, a toy, or an academic interest)
- repeated movements and behaviour (such as hand flapping, hair twirling, spinning around, or listening to something on repeat)
- preference for order, predictability or routine (such as wanting to know what is going to happen in detail, for rules to be the same for everyone, having the same routine or meals each day, or needing a favourite toy to feel calm).
Sensory processing
Autistic people can be much more or less sensitive than non-autistic people to the five main senses (sight, sound, touch, taste and smell) and senses for balance, movement, spatial awareness and awareness of internal states (such as hunger and temperature).
A person may be very sensitive to one kind of sensory input, but not at all sensitive to another. Their reactions can also change depending on the situation and environment.
Sensory processing differences are not a standalone core characteristic. During diagnosis, these are considered part of ‘RRBIs’ (see Behaviours and interests above). This is because of the reactions they may cause (avoiding or seeking out sensory input or showing distressed behaviours).
Last updated: 14/07/2025