Robert Reynolds Macintosh was born in Timaru, New Zealand, on 17 October 1897 the son of Charles N Macintosh, a surveyor who had been a member of the first rugby football team representing New Zealand abroad in 1893, and his wife Beatrice, née Thompson. He was educated at Waitaki Boys' High School a

Born and educated in Trinidad, he obtained an island scholarship to England in 1917 from QRC Port of Spain. Proceeding to St Bartholomew's Hospital for his medical education, he qualified with the Conjoint Diploma in 1924 and then held various appointments, as resident anaesthetist at St Bartholomew