Home » Disability equality law » Is the stammer a disability? » Disability: ‘Physical or mental impairment’

Disability: ‘Physical or mental impairment’

Disclaimer – please read
This page does not apply outside Great Britain.
Last updated 29th March, 2013 (part update 30th August 2020).

Stammering is a physical or mental impairment. It is less clear which it is (physical or mental), but this does not matter. One case suggests the speech aspects are a ‘physical’ impairment.


Stammering is clearly a “physical or mental impairment”.

Is it “physical” or “mental”? This does not matter. However, it may be that stammering is “physical” as regards its effect on speech, and “mental” as regards psychological components such as avoiding situations.

(Bear in mind that to be a disability within the Equality Act 2010, the physical or mental impairment must also have a substantial and long-term adverse effect on one’s ability to carry out normal day-to-day activities.)

‘Physical or mental’ impairment

Stammering is clearly an impairment.

Also stammering is a “physical or mental” impairment. “Physical or mental” is not interpreted narrowly to exclude some types of impairment. (The legislative history (below) endorses this wide approach).

B v Servisair (UK) Ltd 2004, Employment Tribunal
A tribunal rejected the employer’s argument that a speech impediment was not a ‘physical or mental impairment’.

‘Physical’ or ‘mental’?

Which is stammering, “physical” or “mental”?

The main point is that it does not matter – see below Some guidance and cases. It is not necessary to decide whether it is “physical” or “mental”.

Cases indicate that one looks at the ‘impairment’ rather than its cause (eg below Walker v Sita). This appears to involve looking at whether the effects of the impairment are physical or mental. Stammering seems to be “physical” as regards its effect in producing stammered speech. As regards the various ways people try to avoid stammering (see Hiding the stammer), whether it be effects on their speech or eg avoiding particularl situations, perhaps that is a mix of mental and physical.

The causes of stammering should not be relevant under the Equality Act. However research indicates that development stammering (stammering which starts in childhood) is neurological. Structural and functional differences have been found in the brains of people who stammer compared with people who do not. There is also genetic evidence. On both brain and genetic research, see The new neuroscience of stuttering (knowablemagazine.org), February 2020 and The science of stammering (archive of stammering.org), July 2016.

B v Servisair (UK) Ltd 2004, Employment Tribunal
A tribunal considered a ‘speech impediment’ to be a physical impairment.
This case considered speech aspects of the stammer, but not psychological aspects which may be seen as at least partly ‘mental’.

I have a separate page on stammering starting in adulthood which considers “physical or mental impairment” in relation to that.

Some guidance and cases

Walker v Sita Information (bailii.org), 2013 Employment Appeal Tribunal (EAT)
The Claimant suffered from a wide range of symptoms which could not be attributed to a recognisable pathological or mental cause. They were regarded as functional overlay, accentuated by his being obese. The employment tribunal held he did not have a physical or mental impairment because there no physical or organic cause for the symptoms could be identified.

The EAT overturned this. He was disabled. The tribunal should have had regard to the effect of his impairments, not their cause. The impairment, the effects, may be physical or mental, but the impairment need not be caused by something physical or mental. However if the genuineness of the symptoms is at issue (it wasn’t in this case) the absence of a recognised cause may have evidential value in deciding whether the symptoms are genuine. Plainly in this case the claimant had both “physical” and “mental” impairments. “Chronic fatigue syndrome may mix the two; bowel and stomach problems, and knee problems, are physical; anxiety and depression are mental.”

A6 It may not always be possible, nor is it necessary, to categorise a condition as either a physical or a mental impairment. The underlying cause of the impairment may be hard to establish. There may be adverse effects which are both physical and mental in nature. Furthermore, effects of a mainly physical nature may stem from an underlying mental impairment, and vice versa.

A7. It is not necessary to consider how an impairment is caused, even if the cause is a consequence of a condition which is excluded. For example, liver disease as a result of alcohol dependency would count as an impairment, although addiction to alcohol itself is expressly excluded from the scope of the definition of disability in the Act. What it is important to consider is the effect of an impairment, not its cause – provided that it is not an excluded condition. …
2011 guidance, para A6 and A7

McNicol v Balfour Beatty Rail Maintenance 2002, Court of Appeal
“It is left to the good sense of the tribunal to make a decision in each case on whether the evidence available establishes that the applicant has a physical or mental impairment with the stated effects. Such a decision can and should be made without substituting for the statutory language a different word or form of words in an ambitious and unnecessary attempt to describe or to define the concept of ‘impairment’.

A bit of legislative history

The legislative history indicates that ‘physical or mental’ is intended to have a wide meaning.

In the Standing Committee Debates considering the Disability Discrimination Act 1995 (Hansard, H.C., Session 1994-95, Standing Committee E, cols 71,72, 101) the then Minister of Social Security and Disabled People, William Hague, made it clear that physical and mental are intended to be seen in their widest sense and should comprehensively cover all forms of impairment.

20th anniversary of stammeringlaw, 1999-2019