Ivan Pavlov

Nobel Prize winning physiologist Ivan Pavlov is known as the father of classical conditioning, but he wasn't the friendly, bell-ringing dog-lover everyone thinks he was. He surgically implanted spigots in the dog’s jaws to measure their saliva and fed them under very restrictive conditions (strapping them down, etc.). He did the same things on human children. Believed to be street urchins, these children had spigots surgically added to their cheeks and were strapped down with a chute leading directly to their mouth. Pavlov would ring a bell and drop a cookie/biscuit down the chute into the child's mouth. There's even film footage of these experiments on children.