Jaak Panksepp (June 5, 1943–April 18, 2017) was an Estonian-American neuroscientist and psychobiologist who coined the term "affective neuroscience", the name for the field that studies the neural mechanisms of emotion. He was the Baily Endowed Chair of Animal Well-Being Science for the Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology at Washington State University's College of Veterinary Medicine, and Emeritus Professor of the Department of Psychology at Bowling Green State University. He was known in the popular press for his research on laughter in non-human animals. Panksepp was born in Tartu, Estonia on June 5, 1943. His family escaped the ravages of post-WWII Soviet occupation by moving to the United States when he was very young. He initially studied at University of Pittsburgh in 1964, and then completed a Ph.D. at the University of Massachusetts. Panksepp resisted establishment forces in animal research, the most notably B. F. Skinner’s school of behaviorism which held that human emotions are irrelevant and animal emotions suspect. He was ridiculed for wanting to study the neuroscience of affect, and he struggled to find research funding. Panksepp conducted many experiments; in one with rats, he found that the rats showed signs of fear when cat hair was placed close to them, even though they had never been anywhere near a cat. Panksepp theorized from this experiment that it is possible laboratory research could routinely be skewed due to researchers with pet cats. He attempted to replicate the experiment using dog hair, but the rats displayed no signs of fear. In the 1999 documentary Why Dogs Smile and Chimpanzees Cry, he is shown to comment on the research of joy in rats: the tickling of domesticated rats made them produce a high-pitch sound which was hypothetically identified as laughter. Panksepp is also well known for publishing a paper in 1979 suggesting that opioid peptides could play a role in the etiology of autism, which proposed that autism may be "an emotional disturbance arising from an upset in the opiate systems in the brain".