A series of experiments in the early 20th century resulted in finding that rats consumed a lot more drugged water when held alone in a small cage than when in a rat park.
The same quantity of normal water and drugged water, with either heroine or cocaine, was available in both places where the experiment was held. Yet, rats in the park consumed less of the drugged water and never became addicted to it, whereas the rat in the cage kept coming back for the drugged water until it died.
The Vietnam War (1955-1975), according to a YouTube video by Munich-based channel "Kurzgesagt - In a Nutshell," can be viewed as a similar human experiment. During the war, soldiers consumed drugs but stopped and never had to go to rehab when they went back home, because, as Professor Bruce K. Alexander of Simon Fraser University argues, it's not the substance that makes a person addicted but the environment in which they are living.
Find out more details in the video below, which was adapted from Johann Hari's New York Times best-selling book "Chasing The Scream: The First and Last Days of the War on Drugs" and was prepared by the online crowdfunding platform Patreon in collaboration with the book's author.
Cover credit: Still from the video above