The approach widely advocated in medicine, clinical psychology and psychiatry emphasising that interventions and other clinical application must be informed by evidence obtained in robust research evaluations.

In relation to autism, this refers to an outstanding talent, often in the context of other difficulties. The talent may have appeared in early childhood, without having been taught or without the hours of practice which are regarded as required to develop a skill. (See also Savant talent.)

A collective term for mental processes which control behaviour, such as planning, paying attention and being able to transfer attention from one task to another, inhibiting inappropriate responses, remembering and manipulating pieces of information, problem solving and generating new activities and ideas.

A way of systematically gathering evidence, whether about the physical world or about psychological processes and behaviour. By varying one aspect of the situation, whilst holding all others constant (as far as possible) the effects of the change can be measured and a cause-effect relationship established. Psychological experiments usually involve comparing one group of participants (the experimental group) against a control group.

Language that a person produces, typically in written or spoken form. Expressive language difficulty means that the person has delay and/or difficulty in producing language. The person's spoken language will be sparse in vocabulary and/or grammatically and syntactically incorrect. The person is likely to have difficulty in putting thoughts into words, and in using language appropriately in different settings. Difficulty with expressive language is common on the autism spectrum, and is often accompanied by receptive language difficulty.

Occurs when two people look at each other’s eyes at the same time, enabling the exchange of social and emotional information, as well as signalling staging in conversation and attention.

A variant of MRI brain imaging that provides insights into how the brain functions whilst a psychological task is performed. fMRI uses changes in blood flow through the brain to give very detailed information about the brain areas where the activity is occurring, thus shedding light on the function of these regions.

A part of the brain in the temporal lobe, known to play an essential role in recognising faces and for differentiating between different faces, objects and emotions.

Generalisation is when a skill or response is capable of transfer to a different situation or context, e.g. one that is more complex, more ‘real-life’ or involves interacting with different people.

Genes are small sections of very long molecules of deoxyribonucleic acid (DNA). Genes contain the instructions for proteins, which in turn act as the ‘building blocks’ for the development and functioning of all living organisms.