The paper by Selten et al (Reference Selten, Veen and Feller2001) is of interest in the context of methodological developments in cross-cultural research which now demand a much greater level of rigour in defining racial ethnic or cultural groups to reflect the hypotheses and the interpretation of the data (Reference McKenzie, Crowcroft and De BonoMcKenzie et al, 1996). One of the difficulties of international work is that each country tends to use particular labels for particular ethnic and cultural groups which reflects a country's particular experience of migration and immigration. Specifically, the term Hindustanis as used by Selten et al is not meaningful. Hindustanis refers to people of Hindu origin, a religious category. This group is compared with Turkish and Moroccans — national categories reflecting place of birth. Alternatively, Hindustanis might refer to people of Indian origin, whom Selten et al and perhaps other researchers in The Netherlands, generally might refer to as Hindustanis. To justify the use of the term Hindustanis they suggest that British Indians migrated to The Netherlands in the 19th century. Selten et al are suggesting that people retain all the risk factors and cultural beliefs that determine illness behaviour despite exposure to new cultures and that these patterns persist over generations. This is simply not the case. It would have been of more interest to explore specific social factors that might account for their findings while taking account of the specific experiences of the cultural and sub-cultural groups that were more uniformly identified. For example, the ethnic density of each of their groups in comparison to the host population may explain the rates of psychosis (Reference Bhugra and JonesBhugra & Jones, 2001). Social factors such as cultural identity, unemployment and seperation from parents may also explain variations in rates (Reference Bhugra, Leff and MallettBhugra et al, 1997). These factors are entirely unexplored. The use of aggregated ethnic, religious or national groups that do not relate to similar groups makes any explanation or interpretation of their findings impossible, so reinforcing the view that research on ethnic groups bears no relationship to improving service delivery or understanding distress.