First, Foresta is describing a classic addiction process gradual desensitization.

And the message from the top (as Rumsfeld put it, the enemy is not dressed in a uniform these days) fosters further desensitization.

Given the desensitization effect on most male subjects, researchers found that they quickly required higher levels of stimulation to achieve the same level of arousal.

(There is some new evidence, uncovered by Jim Pfaus at Concordia University in Canada, that desensitization may be affecting women consumers of pornography as well.)

Indeed, hardcore pornography s effectiveness in achieving rapid desensitization in subjects has led to its frequent use in training doctors and military teams to deal with very shocking or sensitive situations.