One major reason Americans are dumber than our ancestors is because so many of us are wankers. How good a man is "at life" is directly connected to whether he's spent himself sexually; and, from what I gather, the majority of American men have already wanked themselves dry.
In this matter the ancient Jews have us beat. Even Solomon's mom knew that if a king spent his energy on women he couldn't spend it thinking. But today we aren't even spending our energy on women. Those of us who are spending it on pornography are spending on other people spending it on women. We have all the downsides of exhaustion and none of the self-esteem or the children that come with it.
For all that can be said against him, Solomon could could hold his head high explaining why he was worn out and wrote in short bursts. After the beauty queens it was all he had left. But the average American is dull, and he's gotten so used to being dull, he's begun to believe that dullness is the norm. He believes it because nobody's told him he's a wanker.
Even reading difficult books is impossible when you're spent (try anything by Edmund Burke to prove my point). Women are less exciting to the spent man, which means the man is less exciting because the spent man is less excited. Our continuity of thought gets broken into meaningless fragments, we think that everything is boring, work feels like it's dragging on forever, and it's harder to be funny. Sexual vitality runs so deeply in the male soul that avoiding two extremes is imperative to our success as people in general*. Too little ejaculation and you end up a menace. Too frequent and you end up a potato. And the problem with pornography is in the frequency. Simply put, you can watch pornography all day every day. You have to be a maniac to have sex multiple times a day with a wife of five years. You can engage yourself half a dozen times a day without either an interested partner or a suitable erection. Pornography will eat you alive if you let it, which is why you ought to stay away from pornography.
Christians have been the most vocal critics of a culture of masturbation, but unless they're willing to get explicit in church (which aside from the absolutely horrible Song of Solomon is something like never), they're usually unwilling to tell, publicly, how it has personally affected them. The reason is obvious: because talking about wankery is having everyone imagine you spanking it; and as everyone expects, pastors are supposed to be "better" than the rest of us.
Yes, Christians have all kinds of conferences disguised as "man retreats" where they can get away from their wives and talk about porn. But the fact that they're constantly retreating from a fight nobody seems to be winning proves that the war against wankery needs more than just censure. It needs the conviction that another far-better version of yourself lies somewhere beyond the sermonizing, and that all our spiritual greatness (however unflattering this sounds) is tied almost inseparably to our gonads. It needs the living proof, and probably from experience, that the rush of blood to the brain and the pumping of air through the lungs during actual sex changes something in our neurological makeup, leaving us braver and clearer and healthier in the end. You have to feel that colors are brighter before pornography and afterwards intolerably grayer. Men can be told this, but in the end they ultimately have to live it. And in order to live it, they have to be taught to listen to themselves.
But serious Christians these days aren't known for being good philosophers, because they're taught specifically not to experiment. The whole of their morality lies in commandments: a list of do's and don'ts that comprises the ideal of saintliness. The problem with divine commandments is that you have to get the cart before the horse. With the experience of life, people do things and then we draw general principles from the results and then we get moral authority. With a pretense to a divine authority, you're told things that are indisputable, and then if you want to appear reasonable, you have to try and explain them even if they're ridiculous (the volumes of Jewish and Christian and Islamic apologetics are a testament to this fact).
In short Christians are less worried that masturbation is ruining them personally than that it's ruining them judicially -- a result of the idea of God Himself. A man whose every thought and behavior isn't only scrutinized, but recorded by an omniscient and omnipresent judge, can never commit an act of the slightest uncleanness without the overwhelming terror of being seen. And the thoughts that go through our heads as we chase our sexual fantasies are usually things we'd never speak about to anyone. Ever. So it isn't just that Christians are terrified of being seen at their most embarrassing. It's the unspoken understanding that anyone who isn't embarrassed about it doesn't actually have a God to be embarrassed in front of.
Godliness, in its truest and purest form, is the living of life as though God was personally present. So masturbation and its censure are almost the marks of any really modern Godly man. On the one hand, his sexual fragility makes him a man. On the other, his hatred of it makes him feel really Godly****.
*To prove how important our sexual vitality is to God and ourselves, if you end up starving, your body will eat its own liver before going for your gonads.
***Recent statistics show that the states most responsible for the mass-consumption of porn are the states most responsible for the propagation of the Gospel (and in the case of Utah, the propagation of something like it). Pastors are just as likely to have watched pornography as anyone outside the faith; and whether this is a result of non-believers living in the church or the hypocrisy of actual disciples is beside the point. The fact of the matter is that massive numbers of people claiming to be Christian are also claiming to be upset about pornography -- while funding it.
****All through my youth I remember being genuinely scared of judgment on this issue, even promising God that by my fourteenth birthday I would never, ever sin in this manner again. As anyone may have guessed, my promises ended in failure, and I didn't learn to control myself until a much later age. Not because I was convinced abstinence would make me holy, but because I was convinced that I was way more interesting without wanking. Sexual health is just as much timing as acting.