[2] Together with Nikolaas Tinbergen, Patrick Bateson and Robert Hinde, Thorpe contributed to the growth and acceptance of behavioural biology in Great Britain.
His father Francis Homan was a borough accountant who also worked with the London Missionary Society while his mother took part in the women's suffrage movement and was involved in Christian pacifism.
He closely followed the burgeoning ethological research of Konrad Lorenz and Niko Tinbergen, introducing their work to English readers.
In 1950 he became the first director of the Cambridge Ornithological Field Station; he was appointed Reader in Zoology in 1959 and awarded a personal chair in 1966.
He was a member of the advisory committee to the Anti-Concorde Project and as a vocal conservationist led in saving Wicken Fen from draining and development.