John Watson established the entire psychological field of behaviorism by gallantly conducting experiments on babies. Evidently, getting an baby to work on back in the 20s was easy: You just grabbed one that belonged to one of the hospital's employees... an employee who, it should be noted, was not involved in the experiment. Apart from their relationship to the subject/lab rat, of course.
For this particular experiment, Watson took a baby named Albert and exposed him to rats, monkey masks and burning newspaper. Then he stopped fucking around and began the actual experiment.
Little Albert would be introduced to a series of fluffy white objects, such as a white rat, a white rabbit and a swatch of white fur. Initially, Albert possessed no fear of these things. During subsequent exposures to the same objects, Watson would hammer a steel bar, creating a terrifying racket. In time, whenever Albert saw anything white and fluffy he cried with fear. This is science.
Watson's goal was, of course, to see if it was possible to condition fear in an infant. You know, because prior to this infants were regarded as cold, unfeeling machines, incapable of emotion.
Working tirelessly alongside his assistants, he scared a child for 31 days before returning it to the hospital drenched in terrified excrement (evidently it was just a rental). Unfortunately, Watson spent the entire experiment scaring the shit out of Albert with the hammer of Thor and never got around to actually correcting any of the tremendous psychological damage he was causing, thereby dooming Albert to grow up as a man who pissed his pants at the sight of a cotton ball.
As if this wasn't enough, it turns out Watson had wanted to do more. He lamented that he didn't have the time to condition both fear and arousal in Albert by stimulating the child's erogenous zones during the experiments, because back then getting an infant to shit all over his own boner was considered the pinnacle of behavioral research.