Background: The National Association for Mental Health adopted the "brand name" MIND as part of its transformation into a campaigning pressure group at the turn of the 1970s. This article examines the historical antecedents to key statements made by the organisation at this time regarding the relationship of mental health with, what was then called, "mental handicap". Methods: The National Association is placed within the historical context of the movement for mental hygiene. The article traces how the movement theorised mental health as critically related to intellect and emotionality. Results: The movement relegated people deemed "mentally deficient" from therapeutic policies based on family relationships believed to promote mental health. However, a late 1950s experiment known as the Brooklands study subverted this discrimination. This was paradoxical since it built on mental hygiene theorising. Conclusions: Theorisations of the relationship between intellect, emotion and mental health are still potentially discriminatory.