What’s the Cat Hair?

Karen Jasper writes:

Almost all young mammals, including humans, play. Why is that? In a nutshell, most social scientists believe that play is a way to feel joy and is very very important in how well young mammals evolve. So in 1998 a neuroscientist named Jaak Pansepp conducted in depth studies on young rat pups at play in their cages. He observed them initiating rough and tumble and clearly enjoyable play with each other for four days straight. On the fifth day, he introduced a minimally threatening stimulus into their environment: a hair from a cat. He left the hair in the cage for only 24 hours and then removed it. Guess what happened to the rat pups’ play after the cat hair was introduced and then removed? Click here to find out!