Howard Scott Liddell (November 1895–October 1962) was an American professor of psychology who was involved in the Macy Conferences.
[1] Liddell attended a lecture by Gleb Anrep, a former assistant of Ivan Pavlov given at Cornell in 1923.
In 1924, following Anrep's advice, Liddell went on to set up a laboratory modelled on that of Pavlov.
He experimented on pigs, dogs, sheep, goats, and rabbits.
Liddell then visited Pavlov's original laboratory in Leningrad in 1926 and again in 1934 at the time of his publication of Comparative Psychology.