The behaviours, interests or activities displayed by the autistic person are clearly atypical or excessive in relation to their age and socio-cultural context. Symptoms of ASD in this sphere include:

  • a tendency towards constancy – even trivial changes (e.g. in the environment or daily schedule) can trigger anxiety and tantrums in the child;
  • excessive attachment to routines and rituals, e.g. insisting on eating the same food every day or taking the same route;
  • inflexibility in relation to following rules;
  • stereotypical and repetitive behaviours, use of objects or speech (e.g. shaking objects or arranging them in a line, or echolalia, consisting of repeating – like an echo – words or sentences heard);
  • repetitive and stereotyped motor movements such as whole-body movements (e.g. rocking), atypical gait (e.g. tiptoeing), atypical hand or finger movements and posture;
  • persistent preoccupation with one or more particular interests, parts of objects or certain types of stimuli, or unusually strong attachment to unusual objects;
  • hypersensitivity or hyposensitivity to sensory stimuli or unusual interest in sensory aspects of the environment, e.g. apparent indifference to heat/cold/pain, fascination with lights and rotating objects, inappropriate responses to specific sounds and textures, excessive sniffing or touching of objects.