Ronald Clark's 1979 biography of Einstein states, "he had insisted that his brain should be used for research and that he be cremated", but more recent research has suggested that this may not be true and that the brain was removed and preserved without the permission of either Einstein or his close relatives. Hans Albert Einstein, the physicist's elder son, endorsed the removal after the event, but insisted that his father's brain should be used only for research to be published in scientific journals of high standing.[4]