Autistic people vary enormously from each other but they all have restricted, repetitive patterns of behaviour, interests, or activities of one kind or another.
For example, they may
- have an overwhelming interest in something, such as transport systems or Dr. Who
- stick to specific routines or rituals, such as always going to the shops the same way
- repeat the same movements, such as flapping their hands over and over again
- be hypersensitive to certain sounds, such as telephones
It is worth noting that some autistic people like their repetitive behaviours and consider them useful ways to deal with stressful events.