The recent Mental Health Bill contains among its core concerns the need to address racial inequity in use of the Mental Health Act and a wish to emphasise patient autonomy and capacity more strongly. Although these are important and admirable goals, there is a risk of walking into a quagmire of unstudied problems. Few studies have examined the relationship between mental capacity assessment and race. There are, however, strong reasons to suspect that it is not a panacea – and that it only appears as such because of a lack of study.

It has been well established that ethnic minorities are more likely to experience coercive pathways into care (although perhaps the largest evidence review on this topic found less evidence regarding Roma, Gypsy and Irish Traveller and Chinese groups). ^{Reference Kapadia, Zhang, Salway, Nazroo, Booth and Villarroel-Williams1} Existing work, however, has focused on the use of involuntary detention under the Mental Health Act. Detention under the Mental Health Act has different requirements from those set out in the Mental Capacity Act. Such detention requires that the detained individual have a diagnosis of mental illness, as well as a ‘risk-based’ requirement that the person pose a risk to themselves or others. One possible explanation of the greater use of detention under the Mental Health Act is therefore the stereotyping of ethnic minorities, especially Black people, as more dangerous than White people.

One might therefore think that the general concern about coercive care cannot be generalised to the use of mental capacity legislation. The Mental Capacity Act, after all, is not ‘risk-based’ in the same way. Instead, it proposes a functional test: one has the capacity to make a certain decision if and only if one can understand, retain, and use and weigh the information relevant to that decision and communicate one’s decision to others.

However, dangerousness is not the only stereotype around ethnic minorities. Ethnic minorities, and especially Black people, are often seen as less intelligent – a stereotype with a deep history, closely tied to the history of intelligence testing. ^{Reference Fischer2,Reference Gould3,Reference Lemons4} This stereotype may influence assessments of whether individuals meet the requirements of the functional test described above, especially in relation to criteria 1 and 3. ‘Stereotype threat’ may mean that people perform worse on the relevant cognitive tests as a result of their awareness of this stereotype. ^{Reference Steele5} It is also worth noting that stereotypes of low intelligence deserve more general study in relation to capacity – similar stereotypes may, for example, influence treatment of the elderly and other groups likely to be seen as less intelligent by clinicians, such as those with lower-prestige accents.

One might hope that clinicians have been trained so as not to be influenced by such stereotypes. However, this would not help with the problem of ‘stereotype threat’, in which the effect is mediated by the patient’s awareness of the stereotype. Such a hope is also undermined by evidence of ethnic inequalities in healthcare in general, and in the use of the Mental Health Act in particular. As such, the generally higher rate of use of coercive methods on ethnic minorities and the existence of relevant stereotypes about ethnic minorities that may influence capacity assessment both provide reasons for concern about false negatives in capacity assessment: cases where individuals are denied capacity, despite in fact having capacity.

There is also a risk of false positives. In a false positive case, a person is asserted to have capacity despite lacking it. Capacity assessments are protective as well as coercive: being denied capacity is not always a bad thing, and it may be life-saving. Affirmations of a patient’s capacity sometimes serve as an expression of the assessor’s view that a patient is not worthy of help and treatment – as a denial of concern for the patient. ^{Reference Aves6,Reference Craigie and Davies7} Ethnic minorities are frequently recipients of reduced empathy and seen as less legitimate victims of wrongs – they are also, for example, seen as less affected by pain. ^{Reference Trawalter, Hoffman and Waytz8}

We therefore need to worry about both false positives, based on a lack of concern for ethnic minorities, and false negatives, based on negative stereotypes about the intelligence of ethnic minorities and willingness to apply coercive treatment to them. There is independent evidence of such duality in medical practice around psychiatric illness in ethnic minorities. For example, in the treatment of Black people with schizophrenia, some treatments such as talk therapy are less likely to be offered, whereas other treatments – in particular, highly invasive ones – are more likely to be offered. ^{Reference Kapadia, Zhang, Salway, Nazroo, Booth and Villarroel-Williams1} Owing to the dual risks of both false positives and false negatives, fine-grained comparison and study are needed.