Motor

Mannerisms

A mannerism is an unusual, odd, or stilted way of carrying out an otherwise ordinary, goal-directed movement or maintaining a posture, such as a peculiar way of shaking hands, an odd gait, or an idiosyncratic style of dress or handwriting. The movement remains recognisably goal-directed, just performed in a strange, exaggerated, or out-of-keeping way.

This has traditionally been distinguished by remaining goal-directed, however oddly performed, which sets it apart from a stereotypy, a repetitive movement or posture that has lost any clear goal-directed quality; in practice, the exact boundary between the two can be difficult to draw.

Also known as

Bizarreries

A term used by some authors as a simple synonym for mannerisms, and by others to describe a more severe, grotesque, distorted variety of movement or posture in which no aim or goal can be discerned at all.

Recognition features

• An unusual, stilted, or exaggerated way of performing an otherwise ordinary, purposeful movement, such as shaking hands, writing, or walking
• Can also apply to postures, dress, hairstyle, or manner of speech, wherever an odd, individual, exaggerated quality is superimposed on an otherwise recognisable, purposeful activity
• The underlying goal or purpose of the movement remains discernible, distinguishing it from a stereotypy
• Occurs in people without any mental illness, as well as across a range of psychiatric and neurological conditions, and is therefore not diagnostic on its own

Eliciting it at interview

• Observe ordinary goal-directed activities during the interview, such as greeting, gesturing, and writing, for any unusual, exaggerated, or idiosyncratic quality
• Ask family or carers whether they have noticed any unusual, repeated way the person carries out everyday actions, since mannerisms can become a stable part of a person's presentation over time
• Interpret any mannerism within the whole clinical picture, since it is not by itself diagnostic of any particular condition

Distinguishing features

• Differs from a stereotypy, in which the repetitive movement or posture is no longer clearly goal-directed, whereas a mannerism remains a recognisable, purposeful action performed oddly
• Differs from an obsession or compulsion, in which the person is aware of an internal urge driving the behaviour, whereas mannerisms are typically performed without the same explicit internal sense of compulsion
• Can arise from delusional ideas, catatonic motor disorder, or negativism in schizophrenia, but also occurs in people without mental illness, particularly in the context of anxiety or a wish to be noticed

Common misconceptions

• That any mannerism indicates schizophrenia or another psychiatric illness; mannerisms are common in people without mental illness, including as a feature of adolescence or social anxiety
• That mannerisms and stereotypies are always easy to tell apart; the book itself notes the boundary between the two can be genuinely difficult to draw in practice

Related phenomena

Stereotyped Posture

Diagnostically relevant to

Schizophrenia (catatonic presentations) (links open the DSM-5 Learning Lab)

Practice this

A 30-year-old man with schizophrenia has a distinctive, exaggerated flourish every time he signs his name, sweeping his hand in a wide unnecessary arc before setting pen to paper. His family confirms this habit has been present, unchanged, for several years, and he cannot explain it when asked. What is this? · A 19-year-old university student, with no psychiatric history, has an unusual, exaggerated bow whenever she greets a lecturer, a habit her friends say is 'just her thing' and find endearing rather than concerning. Before revealing the answer: is this a mannerism in the clinical sense, and what does this case illustrate about interpreting mannerisms in isolation? · A patient repeatedly performs an unusual movement. Before revealing the answer, decide what would tell a mannerism apart from a stereotyped posture. · A patient performs an unusual repetitive movement. Before revealing the answer, decide what distinguishes occupational delirium from a mannerism. · You want to check for mannerisms during a mental state examination without over-interpreting ordinary personal quirks. Before revealing the answer, decide what you would actually do. · Explain why a mannerism is not, by itself, considered evidence of schizophrenia or any other specific psychiatric illness.

Illustration

A 30-year-old man with schizophrenia has a distinctive, exaggerated flourish every time he signs his name, sweeping his hand in a wide unnecessary arc before setting pen to paper, a habit his family confirms has been present, unchanged, for several years and which he cannot explain when asked about it.

References

• Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 8, 'Motor Disorders'.