And cheap paperback novels, movies, TV, pornography and video games. The amount of stimulation or positive reward available through these things with only a small effort and a small risk and a short waiting time are much greater than anything available in the environment of evolutionary adaptedness with a similar degree of effort, risk and waiting time.
Not sure if that was an attempt to reduce my argument to an absurdity.. but now we can see many of those things evolve and adapt in real time with lots of testing to reach their maximum potential.
