In 1934 the Eugenics Society issued a statement of policy in its ‘Aims and Objectives of the Eugenics Society’. Under ‘Race Mixture’, it wrote: ‘In certain circumstances, race mixture is known to be bad. Further knowledge of its biological effects is needed in order to make it possible to frame a practical eugenic policy. Meanwhile, since the process of race mixture cannot be reversed, great caution is advocated’. The Society was active throughout the 1920s and 30s, either in publicising or publishing work that had been preoccupied with measuring the physical characteristics of the offspring of interracial unions and in discouraging or condemning race mixing.