In the 1970s, psychologist Bruce Alexander ran a series of experiments on drug addiction amongst rats. There were already numerous experiments showing that rats would perfer a highly addictive drug over water, until the point of death. But Bruce Alexander wondered if this was more due to the setting than the drug, as all these experiments were conducted in Skinner boxes, where they were isolated from any kind of social contact. He built Rat Park, a wooden enclosure as big as 200 cages, with plenty of places for hiding and climbing. He put 16-20 rats of both sexes in it, and gave them plenty of food. He provided two water bottles, one filled with normal water, and the other laced with morphine. The rats overwhelmingly preferred the plain water. Then he sweetened the morphine water. The rats still preferred the plain water. Then he forced the rats to become addicts, offering them only morphine-laced water for 57 days. When plain water was available again, most of the rats went back to plain water. This is consistent with a 1975 survey that showed that out of thousands of soldiers who had become heroin addicts during the Vietnam war, 88 percent of them quit when they left the war zone. --- Source: [[Reference Notes/New Self, New World]]