Freud e Ana Freud(filha)! Estão a observar o post anterior (mind and body)!
"We all know cocaine is an addictive drug: just about the most addictive drug on the planet. In one experiment, a chimp was trained to hit a bar in his cage to be administered with a dose of cocaine. At regular intervals, the number of times the chimp had to hit the bar to get the coke was increased. The experiment was finally abandoned when the chimp hit the bar over 12,000 times to get a single dose of coke"