No, human minds do NOT work the same as dogs (in that respect).
There are MANY factors that trigger drug use in humans.
As to "unexercised" young people, the negative results of lack of exercise is shaped by their entire surroundings - media, technology, habitat, parenting, schooling, peers, etc, etc, etc.
Same goes for obesity, and any number of maladies we see rampant in the U.S. and many other countries.
Take your family to a beautiful DESERTED island with plenty of fish, game and edible natural produce, and NONE of them will become obese, drug addicted, or any other typical first-world problem. EVEN WITHOUT EXERCISE.
