22 AUGUST 1970, Page 23

Saying the unsayable

Sir: The difference between American whites and negroes in respect of intelligence (Frank Hung. Letters. 8 August) clearly can- not be explained entirely by reference to differing cultural background. Is it not possi- ble, however. that the ancestors of American negroes. who were in many cases forcibly transported from their places of origin in Africa, are likely to have been of lower intelligence than those who were left behind, if only because it took some intelligence to escape the slave traders?