He was born in Islington in London in 1841, and began life as a workman. Later, when he lived near Aberdeen, he attended courses without charge. He studied philosophy and literature, but after a year he returned to London. Spalding trained to be a lawyer, but contracted tuberculosis.
He travelled in Europe in hopes of finding a cure. In Avignon he met John Stuart Mill, and through Mill he met John Russell, Viscount Amberley. Russell was the son of the former British Prime Minister Lord John Russell. Spalding became tutor to Viscount Amberley's children, including perhaps the very young Bertrand Russell. He also carried on an intermittent affair with Katharine Russell, Lord Amberley's wife. After the Lord Amberley's death in 1876, Spalding returned to the continent and died there the following year.
Spalding carried out some remarkable experiments on animal behaviour, and discovered the phenomenon now known as imprinting. This was later rediscovered by Oskar Heinroth, then studied and popularised by Konrad Lorenz and Niko Tinbergen.
Instinct and imprinting were the first scientific concepts in ethology. Spalding was able to prove that the behaviour of chicks after hatching from the egg happened even when they had no experience, practice or even information from the senses. Therefore the capacity was inherited. J.B.S. Haldane reprinted Spalding's essay On Instinct in 1954 to show how important it was for the history of ethology.
- Thorpe W.H. 1979. The origins and rise of ethology: the science of the natural behaviour of animals. Heinemann Praeger, London 1979. Chapter 3: The British contribution to the development of ethology through the nineteenth into the twentieth century. ISBN
- One of the professors arranged this.
- Russell was by then the 1st Earl Russell.
- Spalding D.A. 1872. On instinct. Nature, 6, 485-486.
- Spalding D.A. 1873. Instinct, with original observations on young animals. Macmillan's Magazine, 27, 282-293.
- Tinbergen, Niko 1951. The study of instinct. Oxford University Press.
- Spalding D.A. 1873. Instinct in young birds. Popular Science Monthly. 
- Thorpe W.H. 1979. The origins and rise of ethology: the science of the natural behaviour of animals. Heinneman, London, 18-27. ISBN 0435624415
- Gray P.H. 1967. Spalding and his influence on research in developmental behavior. Journal of the History of the Behavioral Sciences. 3, 168-179.
- Haldane J.B.S. 1954. Introducing Douglas Spalding. British Journal for Animal Behaviour, 2, 1.