Today in the History of Psychology (11th May 1917)

John B. Calhoun was born. An eminent behavioral sciences researcher at the National Institute of Mental Health (NIMH), Calhoun conducting pioneering work into social crowding and aggression through observing the behavioral effects of overpopulation within rat colonies.

Calhoun coined the phrase "behavioral sink" to highlight the increasingly aberrant and antisocial behaviors resulting from overcrowding; which he along with other social scientists and public commentators believed served as a clear warning to humankind in respect of human crowding in urban areas.