Glossary

Formal acknowledgment that an organisation or service is committed to understanding autism and making appropriate adjustments to accommodate it.

The ability to employ the practical, everyday skills needed to function, including the skills necessary to effectively and independently take care of oneself and to interact with other people.

A term describing interventions in which an adult (parent or therapist) decides which of a child’s skills are targeted for development or enhancement. (See also child-centred approach.)

A term used for what happens to children with autism once they have become adults. It encompasses psychological and social outcomes, including changes in language processing and use, independence and mental health.

A natural liking for and understanding of someone or something

An almond-shaped structure in the brain located under the cerebral hemispheres. It has an important role in evaluating the emotional significance of external events and in regulating associated behavioural responses such as flushing, trembling or sweating when frightened.

The use of domestic and wild animals (pets or dolphins for instance) to reduce stress, focus attention and improve communication in people with autism. As yet the evidence that this is effective is unclear, although it may be beneficial for some.

A group of comprehensive behavioural interventions evolved from an approach pioneered by Ivar Lovaas and based on the work of Skinner. ABA employs operant conditioning and reinforcement to shape the person’s behaviour, aiming to increase ‘desirable’ behaviours and reduce ‘undesirable’ behaviours. (See also operant conditioning and reinforcement).

A term which has been used in the diagnosis of people on the spectrum who are intellectually capable and with many intact language skills. The main diagnostic classifications, DSM and ICD, are relinquishing this and other sub-types of autism, following recognition that they cannot be reliably distinguished.

The use of technological aids, such as smartphones, video modelling or robots, to assist people with autism or learning difficulties in daily living or to learn new skills.

A condition characterised by inattentiveness, hyperactivity and impulsiveness. Although not linked to intelligence, ADHD may disrupt learning.

A cognitive style especially associated with autism characterised by focusing closely on the specifics or details of task rather than the overall picture.

An interview designed for use with the parents of children or adults who are being assessed for an autism spectrum diagnosis. The ADI comprises questions about the offspring’s current skills and behaviours, as well as how these behaviours were manifested at age four to five years or at any point during development. The original version of the instrument (the ADI) was often used to verify diagnoses for research purposes. The revised version, designed for diagnosis in clinical settings, was published in 2003.

An interactive assessment tool used in making autism spectrum diagnoses. It consists of four separate modules, each comprising tasks designed for use with children of different ages and different levels of development and language.

A network of people with autism that advocates that autism is a form of human variation (a neurodiversity), rather than a disorder to be cured, and that society needs to be accepting of autistic behaviours, teaching coping skills rather than trying to make autistic people neurotypical. The movement also organises social events where autistics can ‘be themselves’.

A description of the fact that whilst all individuals with autism share some core characteristics, they also have their own unique profile of strengths and weaknesses.

A term favoured over Autism Spectrum Disorder by some professionals and people in the autism community as it avoids the negative connotations of ‘disorder’.

The term used in formal diagnosis, and by many professionals in the context of clinical practice for diagnoses on the autism spectrum. Autism Spectrum Disorder is a neurodevelopmental condition characterised by moderate to profound difficulties in social communication, and restricted and repetitive behaviours and interests.

See broader autism phenotype.

The application of principles of learning and conditioning to influence or improve a person's behaviour, by eradicating “maladaptive behaviours” and promoting the learning of new ones through reinforcement of behaviour. Based on the work of B.F. Skinner, and pioneered in the autism field by Ivar Lovaas.

This suggests that the causes of a condition are rooted in a person’s biological make-up, that is, their genes and the structure and function of the brain and other components of the nervous system.

In experiments and observational studies, this refers to the procedure in which the researcher evaluating the behaviour does not know which participants are in the experimental group and which are in the control group.

The means by which information about thoughts, feelings or attitudes is communicated non-verbally, either consciously or non-consciously. Includes facial expressions, gesture and posture, as well as the use of space.

Milder manifestations of traits characteristic for autism in relatives of people with autism.

Acronym for Child and Adolescent Mental Health Services, services within the UK National Health Service that assess and treat young people with emotional, behavioural or mental health difficulties. Usually a multi-disciplinary team including psychologists, psychiatrists and other specialists.

A gene whose function, or location on a chromosome, suggests that it might be associated with a condition or disorder.

In-depth observation and description of the specific characteristics of a selected individual. Pooling of case study material across individuals may permit identification of general features. The method is used by clinical practitioners, and in some forms of research.

An approach which some have misleadingly claimed alleviates or cures autism by eliminating ‘excess toxins’ from the body. Described by the UK’s National Institution for Clinical Excellence (NICE) as harmful and to be avoided.

A term describing interventions which involve following the child's own interests and motivation as a means of encouraging interaction and learning. (See also adult-directed approaches.)

Structural units in all living cells, composed of long strands of DNA along which genes are located. (See also deoxyribonucleic acid (DNA) and genes.)

The psychological processes involved in thinking, learning, planning and problem-solving, and in the understanding and use of language.

Characteristic strategies or preferences for thinking and processing information.

A medical term for the presence of one or more conditions or disorders alongside a primary condition. In autism, epilepsy is a common co-morbid condition.

The extent to which the same (or a similar) condition, characteristic or trait is present in both members of a pair of twins or siblings.

A sequence of items or entities running along a continuous scale such that differences between items are gradual rather than abrupt.

A group of participants in an experiment or other systematic study used as a standard against which others are measured. This could be a group who do not receive an intervention, or it could be a group who do not have autism.

A formal evaluation of an intervention, with more participants than a pilot study. Typically it would involve two groups of participants on the autism spectrum, matched for level of symptoms, age and IQ. One group receives the intervention and the other receives no intervention or treatment as usual. Comparing the groups’ skills and behaviours after the study permits efficacy of the intervention to be evaluated.

A legal document in Scotland drawn up by the local authority, after specialist reports are obtained, which specifies the support a child or young person up to age 19 needs in school.

Complex molecules in cells that contain the instructions necessary in the development and functioning of all living organisms. DNA consists of long twisted strands, each composed of a precise sequence of units. Sections of these units form genes.

Describes a condition or process which unfolds during child development. Development may reflect a typical pattern in which certain skills and behaviours are attained, following broadly the same time frame in different children. In atypical development, for instance in autism, certain key processes such as language and communication develop at a different rate, in a different way or not at all. (See also developmental trajectory.)

A term for the developmental sequence. This emphasises two facets of typical development: (1) There is a characteristic sequence of 'milestones' such as crawling, sitting up and walking. (2) Early developmental skills such as pointing and looking are thought to lay the foundations for later more sophisticated skills such as play with siblings, friendships with peers, or the complex relationships of the teenage years and adulthood. The idea of an atypical developmental trajectory is an important concept in work on autism.

The American Psychiatric Association's formal system for the classification and diagnosis of psychiatric, mental health and developmental conditions, which includes criteria for diagnosing autism. The 5^th edition, published in 2013, dispensed with the diagnostic sub-types of autism (e.g. Asperger Syndrome) seen in earlier versions. The DSM-5 approach to classifying and diagnosing autism treats it as a continuous spectrum and uses severity scores and specifiers to characterise each individual’s strengths and weaknesses.

Formal descriptions of medical, psychiatric and developmental conditions, used in making diagnoses. The criteria comprise a list of symptoms or features that an individual must have for a condition or problem to be diagnosed, and in some cases specify additional symptoms that should not be present. (See also DSM and ICD.)

A set of systematic procedures used to diagnose conditions like autism, for which no medical test can be applied. Diagnostic instruments involve questionnaires, observations of the person and interviews with the family (where possible). The instruments are designed such that the diagnostic criteria are applied in a standard consistent way.

An interview designed for use with the parents of children or adults who are being assessed for an autism spectrum diagnosis. The interview offers a 'dimensional' framework, allowing for ‘graded’ evaluation of how closely an individual matches the criteria for a pervasive developmental disorder, as defined in the ICD and DSM systems.

A specific developmental condition characterised by problems with reading, writing and spelling as a result of underlying difficulties in processing and remembering information. It is not linked to intelligence.

A three-month education programme run by the UK National Autistic Society (NAS), providing support and encouragement and promoting good practice for parents of newly diagnosed children aged under five years on the autism spectrum. EarlyBird Plus is for parents of children aged four to eight years.

An intervention for pre-school children on the autism spectrum, using a range of behavioural techniques based on Applied Behavioural Analysis (ABA) principles. Early forms of intervention such as EIBI have proved very effective with some children. However, intensity for the child and demands on parents are issues for consideration.

The repetition of words, phrases or sentences just spoken by others, in a 'parrot-like' fashion. Echolalia is common in individuals on the autism spectrum, and also occurs in conditions such as schizophrenia and Tourette's syndrome. In autism, the repetition may be immediate or delayed.

A legal document in England drawn up by the local authority, after specialist reports are obtained, which specifies the support a child or young person up to age 25 needs, particularly in school, but also from health and social care.

A test of the capacity to identify an individual component or shape from a visual pattern in which it is embedded.

Empathy is broadly defined as the capacity to understand and 'enter into' another person's emotions. Empathising has been defined by Baron-Cohen as recognising what someone else is feeling and responding appropriately. This may mean feeling the same emotion yourself, e.g. feeling sad when someone else is, and/or showing them that you recognise their emotion, e.g. by trying to comfort them. (See also Empathy Quotient (EQ), Empathising-systemising theory, Systemising and Systemising Quotient (SQ).)

A theory formulated by Baron-Cohen, which proposes that autism is characterised by limited empathising ability, combined with enhanced systemising.

A questionnaire based measure of empathising devised by Baron-Cohen and colleagues. A person’s overall test score on the EQ is assumed to reflect their ability to empathise. Each member of a population can receive a low, high or average score. On average, females tend to score highest whereas people on the autism spectrum generally have the lowest scores, although there is also considerable overlap. (See also Empathising, Empathising-systemising theory, Systemising and Systemising Quotient (SQ).)

Most of a person’s inherited characteristics are due to the sequences of units within the genes making up their DNA, these changing from one generation to the next. Epigenetic influences refer to additional changes in genes which are not due to changes in the DNA sequence, but involve the addition or removal of small molecules to the outside of the gene. These may determine whether the gene is ‘switched on’ or ‘switched off’, thus affecting whether a characteristic coded by the gene is expressed or not.

Objective assessment of an intervention, assessing its effectiveness, which people with autism might benefit from it and whether there are any side effects.

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.

Refers to the influence that genes have on physical and psychological traits. Gene variants inherited from one or both biological parents influence susceptibility to autism.

The term for a condition or disorder in which variants of different genes are involved in different individuals. Except in rare cases, autism is genetically heterogeneous: the genes that play a role in one individual’s autism are likely to be different from the genes involved in another individual’s autism.

Within a programme launched by the Ethiopian Ministry of Health in 2004, health extension workers are women who have received one year of training in delivering primary healthcare. They work in rural areas from simple health posts, providing inoculations, health advice and basic treatments.

The way that physical and behavioural traits and characteristics are passed from biological parents to offspring through the mixing and recombination of genetic material that occurs at fertilisation.

Heritability is the extent to which a condition or feature can be attributed to genetic influences. If a condition is highly heritable, it means, for instance, that parents may pass on to their children genetic variants linked to heightened risk of developing autism. Genetic variants linked to autism may also arise afresh (through new mutations) without being inherited from parents.

Except in rare cases, autism is genetically heterogeneous: the genes that play a role in one individual’s autism are likely to be different from the genes involved in another individual’s autism.

A term used by some specialists to describe cases of autism where the individuals’ full-scale IQ scores are above 70. This is not a formal diagnostic category, but rather a term sometimes used informally in diagnosis, as well as in everyday situations and research. It has sometimes been used interchangeably with Asperger syndrome. The overlap between the two meanings has been questioned, and 'high-functioning' may also give the misleading impression that an able person's experience of autism is mild and not disabling. See also low-functioning.

A group of chemical substances that play a major role in transmitting signals around the body, helping to regulate physiological activities such as digestion and respiration, and psychological states such as stress, mood and social bonding.

All the genetic information carried by the DNA sequences which make up the chromosomes of each human cell.

A prediction about the results of an experiment, based on previous theory and findings concerning the phenomena that the experiment is designed to investigate. The hypothesis is formed before the experiment takes place.

A term used for the insights contributed by people with autism based on their own experience of the condition.

The overall score that a person achieves on a standardised test of verbal and non-verbal abilities, which indicates how well they perform in comparison to others of the same age.

The World Health Organisation's formal system for the classification and diagnosis of physical, psychiatric, mental health and developmental conditions. The current edition (ICD-10) reflects the older sub-type approach to diagnosing autism, whereas the next edition (ICD-11) due in 2018 will be more aligned with the DSM-5 approach.

The group in a controlled intervention evaluation study who receives the intervention. (See also Randomised Control Trial, Controlled Study.)

Procedures for supporting and improving the development, functioning and well-being of someone with autism, helping them to engage with others, thrive and fulfil their potential.

The characteristic rise and fall of speech, which plays a role in communication. People with autism may have difficulty interpreting intonation in speech, or may have unusual intonation themselves. (See also non-verbal communication.)

The phenomenon in which one person coordinates or shares their attention with another, in order to focus on the same object or event. Joint attention emerges in typically developing children by about 12 months of age. Children later receiving autism spectrum diagnoses often show poor joint attention skills.

A term sometimes used for the form of autism with profound social and communication difficulties often including little or no speech, markedly restricted and repetitive behaviour and interests, and intellectual disabilities.

A study which follows the same participants over a substantial period of time – usually several years.

The term used by the World Health Organisation and other international agencies to refer to countries where income falls below a certain level. A more meaningful category than ‘developing countries’ or ‘under-developed countries’, terms which are nowadays regarded as inappropriate.

A term used by some specialists to describe cases of autism where the individuals' full-scale IQ score is below 70, i.e. in the disabled range. This is not a formal diagnostic category, but rather a term sometimes used informally in diagnosis as well as in everyday situations and research. See also high-functioning.

A widely used brain imaging technique that passes magnetic currents harmlessly through the brain to reveal the structural anatomy, and how particular regions may be altered (e.g. larger or smaller than is typical) in conditions such as autism.

An intense response to overwhelming situations which can look like a temper tantrum. An autistic person may shout, cry or scream, kick, lash out or bite, or a combination of these, as a way to express their distress, stress or anxiety.

Refers to a person’s beliefs, memories, desires, intentions and feelings.

A study, usually with a small number of participants, often in the same setting, who start the intervention after having been observed beforehand for differing lengths of time. For example one may start the intervention after 3 weeks, one after 5 weeks and one after 7 weeks. If each is seen to respond positively to the intervention this provides evidence that it is effective and the changes seen are not due to another factor.

Families with more than one child/family member on the autism spectrum. The fact that autism quite commonly affects several family members provides strong evidence that genetic factors play a role in causing autism.

Changes in the sequence of units making up the genes in a person’s DNA. Sometimes parts of a gene may become duplicated, deleted or changed in other ways. Such genetic variation will affect the proteins that are coded for by the DNA, influencing how parts of the body, including the nervous system develop, with consequent effects on behaviour or traits.

A UK framework for the identification, assessment, diagnosis and access to early interventions for pre-school and primary school aged children with autism spectrum conditions.

The National Autistic Society was founded in 1962 as an organisation for people with autism, their families and carers. It provides advice and support for families and autistic individuals, promotes exchange of ideas and information, pioneers important national and international initiatives and raises public consciousness about the needs of people on the autism spectrum.

A term describing interventions that support the development of target skills within a child's everyday environment, or in naturally occurring situations. They may employ some behavioural principles, but are more child-centred than adult-directed. (See also adult-directed approach; child-centred approach.)

The branch of science which focuses on the biology of the nervous system – the structure and functioning of the brain and the nerves which run throughout the body taking signals to and from the brain.

The idea that the kinds of difference seen in conditions such as autism, ADHD and dyslexia arise from natural genetic variation within the population and should be regarded as a normal aspect of human existence, not as something pathological that needs to be treated or cured.

A cell type in the brain and nervous system, which is specialised for processing and transmitting information. Neurons have long thin fibres which collectively make up the nerves of the body.

A chemical involved in carrying a signal from one neuron to another across gaps between neurons known as synapses.

The term neurotypical (NT) was first used within the autism community to denote people who are not on the autism spectrum. The implication is that their brain and mental functioning is typical rather than atypical, particularly in relation to communication and social interaction. The term avoids the problematic connotations of ‘normal’ and ‘abnormal’. It has been quite widely adopted, and is recommended by the National Autistic Society.

The use of non-verbal means, including prosody (pitch, intonation and stress), facial expression and gestures, to express meaning in communication.

Methods widely used in the natural and social sciences. Observational methods typically focus on naturally occurring behaviour, thus contrasting with experiments, which study responses to specially devised tests in a controlled setting. Observational studies may, like experiments, compare a target group (say of autistic participants) with a control group. The observational method usually involves coding of the observations, analysing this information either quantitatively (e.g. scoring or counting particular behaviours) or qualitatively (a more holistic appraisal).

This is an anxiety condition in which a person repeatedly experiences unwelcome thoughts, images, urges, worries or doubts and tries to allay these by carrying out an activity repeatedly, for instance repeatedly checking that a door is locked. Due to the repetitive nature of the compulsions, they may have a serious effect on the person’s ability to carry out daily tasks.

B.F. Skinner’s key principle of learning, stating that all animals’ behaviour operates on the environment with consequences that modify the tendency to repeat the behaviour. Rewarding consequences make repeating the behaviour more likely. Skinner called this reinforcement. For instance, if a non-verbal child is rewarded for making a verbal request this should reinforce the occurrence of this behaviour. These ideas are central to the ABA approach to autism intervention. (See also reinforcement and ABA.)

A developmental outcome in which an autistic person’s symptoms have modified or ameliorated to such an extent that the diagnostic criteria for autism are no longer met.

A measure of the extent to which a particular skill or behaviour targeted by an intervention has changed or improved at the end of a controlled study.

A term used to indicate that descriptions of autistic behaviour and experience come from the perspective of someone who is not themselves autistic. Usually this is a researcher, clinician or other professional.

A hormone which is generated in the brain and released into the bloodstream. It has several functions, including in childbirth, breast-feeding and sexual activity. It is also involved in social bonding, and some research suggests that oxytocin treatment may facilitate social interaction in autistic people.

A highly controversial and potentially harmful intervention, involving wrapping a child in wet towels. Described by medical journal The Lancet (2011) as an abuse of human rights.

Acronym for Pre-school Autism Communication Therapy, an intervention which trains parents to enhance the communication skills and language development of their own children, commencing as early as possible after diagnosis. Parents learn to tailor their own language and interactions to facilitate their child’s communication and participant. PACT also stands for Pre-school Autism Communication Trial, the RCT which has evidenced the effectiveness of this approach.

A free UK-wide confidential telephone service provided by the NAS where the parents of offspring with autism can seek emotional support through talking to another trained parent with personal experience of autism.

Relating to, or caused by, a medical disorder such as a disease.

Acronym for Picture Exchange Communication System, an intervention widely used in clinical, educational and home settings, in which children are taught to communicate using pictures and other symbols. PECS is naturalistic and especially helpful for children with little or no language.

An approach intended to allow a person as much input as possible into decisions about their own care and support needs, in order to increase their self-determination and improve their independence. It focuses on what is important to them, with family and friends as partners in planning.

A preliminary study conducted in advance of a full-scale research study. In clinical work, a pilot may be an informal evaluation of a proposed intervention involving a single participant or a very small group of participants.

Refers to whether a sound is high or low. The pitch of speech plays a role in communication and may be atypical in people on the autism spectrum. (See also non-verbal communication.)

A condition or trait that is due to the combined effects of multiple genes (as opposed to the influence of a single gene). This applies to all but a small minority of autism cases (for instance those where autism is associated with a single gene disorder called neurofibromatosis). In autism the role of multiple genes is further complicated because different gene combinations may be involved in different individuals. (See also genetic heterogeneity.)

A type of play in which children use imagination to enact events or scenarios they may have experienced or that are completely imaginary. It can involve taking another person’s perspective, manipulating ideas and emotions (‘role-playing’) or the imaginative use of objects as props.

An estimate of the number of cases of a condition within a population at a particular time. Prevalence is estimated by identifying how many people in a population sample have been diagnosed with the condition, or who would in principle meet the diagnostic criteria. Prevalence (e.g. of autism) does not necessarily indicate how many people have the condition: cases may go undetected due to factors such as low cultural awareness or limited availability of diagnostic services.

A prediction offered by a medical or other expert concerning the probable course and outcome of a disorder or condition.

Protodeclarative pointing is the use of pointing to draw someone else's attention to an object or item of interest, thus enabling an individual to share their interest with another. Thus a child might point to a bird so that his mother will look at it too. Children on the autism spectrum tend not to use this form of pointing, though they may use protoimperative pointing to indicate an object or item that they want or desire, such as pointing to a biscuit to indicate they want to have it.

Refers to the way the mind works to interpret information about the physical world and social world, and to respond appropriately. This includes perceptual processes such as recognising objects and events, and communicative process such as understanding language, perceiving and interpreting other people’s behaviour, including their gestures and facial expressions, and communicating both verbally and through one’s own behaviour.

This is the scientific study of the way the mind (generally the human mind) works and how this dictates and influences behaviour. Processes investigated include communication, memory, thinking and emotion.

Techniques that provide ways of measuring intelligence, language skills and other cognitive and behavioural capacities or traits.

The general well-being of a person and how they experience their life in terms of comfort, happiness and fulfilment. Factors affecting quality of life include health, relationships, employment and finance.

A questionnaire is a set of questions, often with multiple-choice answers or a scale (from ‘strongly agree’ to ‘strongly disagree’ for instance) to be completed. It can be used to explore attitudes, preferences or personality traits; it may also be used as part of the diagnostic procedure to find out about a person’s behaviour. (See also surveys.)

A systematic evaluation of an intervention in which participants are assigned randomly to intervention and ‘no treatment’ or ‘treatment as usual’ groups. This avoids biases in the way participants are allocated to groups, which could otherwise affect the outcome, making the intervention itself difficult to evaluate. RCTs are typically large-scale studies involving many participants. (See also intervention group; treatment as usual group.)

The process of receiving and understanding language which is spoken or written by others. Difficulty with receptive language means that the person has delay and/or difficulty in making sense of what other people say or write down. Problems are likely to include difficulty in understanding vocabulary or grammar, difficulty in distinguishing speech sounds and in understanding the meaning of sentences. Difficulty with receptive language is common on the autism spectrum and is often accompanied by expressive language difficulty. (See also expressive language.)

In terms of communication and social interaction this means the two-way use of language and turn-taking in conversation, with each person listening to and responding to what the other has said, with coordination to avoid excessive interruption of the other. It also involves responding to another’s actions in order to meet the other person’s expectations and build relationships.

A central principle in behaviour modification and behavioural intervention. Involves shaping an individual's behaviour through the operation of influences known as reinforcers because they increase or decrease the frequency of a particular response. A sweet would be a simple example of a reinforcer given to a child who has managed to articulate a request for the first time. But not all reinforcers are so obvious. (See also operant conditioning.)

Replication is when an experiment, or other study, is repeated under the same conditions to discover if the same results are obtained. Demonstrating that a result is replicable is an important feature of scientific methodology.

A special school equipped so that children with autism or other special needs can stay throughout the week, or even for longer periods. Caters for children with complex needs that cannot be met in mainstream school or in a daily special school.

The ability to withstand hardship and to overcome adversity, becoming stronger and more resourceful as a result.

One of the two main diagnostic criteria for autism. RRBIs involve repeating the same physical activity over and over again, such as flicking fingers or watching the same video, sticking to the same routines and/or being exclusively interested in very few topics, or a single topic, for lengthy periods of time.

An experimental test of a person’s ability to understand that another person may have a different belief about a situation, one which differs from current reality and is thus ‘false’. This test involves a scenario enacted by two dolls called Sally and Anne and the movement of a marble when one is absent. The test is whether the person observing the scenario understands that the character who has been absent will not know that the marble is not in its original position. (See also Theory of Mind.)

A term used for those with profound difficulties in most areas who display an exceptional talent in one area such as art or music.

This is a condition, seen especially in children, in which a person does not speak or communicate effectively in situations where they do not feel comfortable, secure and relaxed. For instance, a child may not speak – or indeed attempt any communication – at school, yet do so at home with their close family. In many cases, selective mutism can be attributed to extreme social anxiety. When it occurs with autism, it may be part of a more fundamental communication problem.

A person’s capacity to reflect on their own thoughts, feelings and traits.

Heightened sensitivity to sounds, tastes, visual and other stimuli, compared with what most people experience. Common in people on the autism spectrum. (See also sensory hyposensitivity.)

Reduced sensitivity to sounds, tastes, visual and other stimuli, compared with what most people experience. Common in people on the autism spectrum. (See also sensory hypersensitivity.)

Broadly defined as a state in which individuals are exposed to so many sensory stimuli, or to stimuli at such high intensities, that they become unable to deal with them. For instance, they may become very stressed and/or become unresponsive to sensory input. In autism, hypersensitivity to sensory stimuli means that a person may experience overload even for moderate levels of stimulation that would not be disagreeable for a person without autism.

The means by which we acquire information about the environment through specialised sense organs, each of which deals with a different modality or dimension of input (sound, smell, taste etc.).

A neurotransmitter involved in complex brain processes, including the regulation of mood, emotions, aggression, sleep and body temperature.

Relatively informal evaluation of an intervention which precedes a full-scale controlled trial. Small-scale evaluations involve testing the intervention with a small number of individuals and usually include observations before, during and after it has taken place.

This involves all forms of interaction between two or more people, ranging from the use of spoken language, facial expressions, gestures and body language to making friends and forming long-term relationships.

This approach to explaining the causes of behaviour, including the development of conditions such as autism, identifies children’s social environment as the key factor. This means influences such as parenting style and the quality of social and emotional interactions the child has with other people.

In relation to autism, this refers to an intense and focused interest in a particular subject or topic, which may in some cases seem unusual or eccentric. Autistic people often have just one or two special interests which they pursue for a long time. They may acquire very detailed knowledge or skill and approach their interest with an intensity that tends to exclude other subject matter. Yet evidence suggests that special interests can be beneficial.

A school or stand-alone unit whose main purpose is to provide education tailored to the additional support needs of children and young people with significant special educational needs. Some special schools are designed specifically for children on the autism spectrum, while others cater for a range of special needs. This definition refers to the UK, but similar provision exists in some other countries.

A health professional whose role is to assess and treat children and adults with speech, language and other communication difficulties.

This is where an individual has a skill in one specific area, such as numeracy or art, which does not characterise their overall abilities or level of functioning. For example, an individual with a low IQ may nonetheless be able to complete complex jigsaw puzzles. Very exceptional levels of such skill are referred to as savant talent. (See also savant talent.)

A legal document in Wales or Northern Ireland drawn up by the local authority, after specialist reports are obtained, which specifies the school-related support needs for a child or young person up to age 19.

A term meaning that the result from an experiment or evaluation of an intervention is highly unlikely to have occurred by chance. If the statistical probability of a chance result is calculated to be sufficiently low, the researcher may reasonably conclude that the result is due to the influence under investigation. For instance, the researcher may conclude that an intervention really has helped the individuals who have participated, or that autistic and neurotypical people really do differ in how they respond to sounds.

A short-hand term for self-stimulatory behaviour or self-stimulation. The repetition of physical movements and sounds, and the repetitive manipulation of objects, which are common in individuals with developmental conditions, and especially in autism, are thought to have pleasant self-stimulatory effects.

The use of emphasis within speech to mark particular words or phrases. Stress plays a role in communication, and may be atypical in people on the autism spectrum. (See also non-verbal communication.)

A survey is a research method in which questionnaire responses are gathered from a large sample of people. These responses are then analysed statistically, to establish trends in those sampled.

Features or characteristics that may indicate a clinical problem or disorder. In some medical conditions (e.g. flu), symptoms may be feelings that the individual experiences and reports to a doctor. In other conditions, such as autism, an individual's symptoms are more likely to be atypical behaviours observed by others such as the individual's parent, or a clinician. Symptoms form the basis for formal diagnostic classifications.

A small gap between two neurons where the transmission of signals takes place via neurotransmitters, chemical messengers that cross the gap.

A term denoting a characteristic combination of symptoms, usually assumed to be caused by a specific underlying disorder, even if the causal mechanism is not well understood. Many syndromes are named after the physicians credited with first reporting the association, hence Kanner's syndrome and Asperger syndrome. Autism is now considered more as a spectrum rather than specific syndromes.

Systemising is defined by Baron-Cohen as the drive to analyse or construct systems, where a system is any domain that lends itself to rules predicting or explaining how the domain works. The precise scope of this idea is vague: it is usually related to subject matter such as science, engineering and maths, but other domains could also be defined in terms of systems and rules. Baron-Cohen proposes that people with autism have a cognitive profile characterised by a high level of systemising ability, together with limited empathising ability. (See also empathising, Empathy Quotient (EQ) and Systemising Quotient (SQ).)

A questionnaire-based measure of systemising devised by Baron-Cohen and colleagues. A person’s overall test score on the SQ is assumed to reflect their ability to systemise. Each member of a population can receive a low, high or average score. On average, females tend to score lowest whereas people on the autism spectrum generally have high scores, although there is also considerable overlap. (See also empathising, Empathising-systemising theory, and systemising)

Acronym for Treatment and Education of Autistic and Related Communication Handicapped Children, a ‘whole person’ intervention supporting many aspects of functioning, including learning, behaviour, social and communication needs, and applicable across different settings (at home, school, in respite services and other locations) as well as across the person’s lifespan. TEACCH aims to maximise an individual’s strengths, drawing on traits such as the need for structure and good visual memory.

A theory offers an explanation of how and why something occurs and may also identify the cause. Theories are derived from research findings and also inform the ongoing development of research.

A person’s understanding of other people’s thoughts, knowledge, beliefs and feelings, including recognition that these may be different from their own. Also sometimes referred to as ‘mindreading’. Many people on the autism spectrum have difficulty with this.

A task in which a set of differently sized rings have to be transferred from one peg to another in the fewest moves but with certain constraints, such as not being able to place a larger ring on a smaller one. Used as a test of executive function.

A common procedure in a controlled intervention study where the participants who do not receive the intervention under evaluation receive a standard intervention or one that they have been receiving previous to the evaluation.

This denotes the fact that in conversation a person generally does not interrupt what another is saying, but waits until there is a suitable gap and responds by following on from their point(s). People with autism may have difficulty with turn-taking, appearing impolite because they interrupt the other person, perhaps with a comment that seems irrelevant to the topic. (See also reciprocity.)

A research method used to evaluate how frequently a particular condition or characteristic co-occurs in both members of monozygotic (identical) twin pairs as compared with dizygotic (non-identical) twins. Higher co-occurrence (concordance) in monozygotic twins provides evidence that the condition or characteristic is genetically inherited. Used in exploring the genetic basis for autism.

Term used (e.g. in research) to denote the kind of development which is seen in the majority of the population, as contrasted with the characteristics of people with a condition such as autism. It is often used in describing children as that is when most development is expected to occur, and when certain key milestones (such as walking and the onset of speech) are typically attained in a broadly regular sequence. (See also neurotypical.)

Finding some sights, sounds, tastes, smells or touch distressing or unbearable (see sensory hypersensitivity). Alternatively appearing not to notice some sensory stimuli (see sensory hyposensitivity).

Slight changes in the DNA sequences which makes up genes, as a result of mutations. Such changes may alter the instructions coded by a gene, leading to alterations in physical or psychological traits and behaviour.

A term sometimes used for the cognitive style characterised by focusing on individual details rather than the overall form, meaning or gist. In autism this may be especially apparent in the visual processing of scenes, and in language processing, where word meanings are processed individually rather than in their context within sentences. However, the evidence for this processing style in autism is mixed.