Ivan Pavlov

Russian physiologist (1849–1936), Nobel laureate in medicine in 1904 and author of the research on conditional reflexes that gave behaviourism its founding experiment. Two things usually confused are worth saying at once: the Nobel was not for the dogs and the bell but for his work on the physiology of digestion, and he did not consider himself a psychologist but a physiologist — to the point of fining collaborators who described the animals in mental language.

He had studied at the seminary before leaving it for natural science at St Petersburg, and made his name with extraordinarily careful surgery: fistulas and gastric pouches that allowed secretions to be collected from a healthy, awake, unanaesthetised animal, which almost nobody could then do. It was precisely that arrangement that put before him the phenomenon which at first annoyed him: the dogs salivated before receiving food, on hearing the footsteps of whoever was bringing it. The "psychic secretion" was an experimental nuisance, and he chose to study it instead of eliminating it.

From this come the concepts that have since travelled on their own: unconditional and conditional reflex, acquisition, extinction, generalisation and discrimination. The name in fact arrived wrong: the Russian is *условный*, "conditional" — dependent on a condition — and the "conditioned" of the English translations is a translator's accident that has lasted a century. With the Soviet regime he had a well-known and uncomfortable relationship: generously funded and openly critical of those in power, he wrote to Molotov protesting the treatment of intellectuals.