euphoria with depression, hunger with satiety. The main difference between opposing emotions and complementary colors is in how they change with experience. With the emotions, a person’s initial reaction gets weaker over time, and the balancing impulse gets stronger. As an experience is repeated, the emotional rebound is more keenly felt than the emotion itself. The first leap in a bungee jump is terrifying, and the sudden yoiiiiing of deceleration exhilarating, followed by an interlude of tranquil euphoria. But with repeated jumps the reassurance component strengthens, which makes the fear subside more quickly and the pleasure arrive earlier. If the most concentrated moment of pleasure is the sudden reversal of panic by reassurance, then the weakening of the panic response over time may require the jumper to try increasingly dangerous jumps to get the same degree of exhilaration. The action-reaction dynamic may be seen with positive initial experiences as well. The first hit of heroin is euphoric, and the withdrawal mild. But as the person turns into a junkie, the pleasure lessens and the withdrawal symptoms come earlier and are more unpleasant, until the compulsion is less to attain the euphoria than to avoid the withdrawal.
According to Baumeister, sadism follows a similar trajectory.259 An aggressor experiences a revulsion to hurting his victim, but the discomfort cannot last forever, and eventually a reassuring, energizing counteremotion resets his equilibrium to neutral. With repeated bouts of brutality, the reenergizing process gets stronger and turns off the revulsion earlier. Eventually it predominates and tilts the entire process toward enjoyment, exhilaration, and then craving. As Baumeister puts it, the pleasure is in the backwash.
By itself the opponent-process theory is a bit too crude, predicting, for example, that people would hit themselves over the head because it feels so good when they stop. Clearly not all experiences are governed by the same tension between reaction and counterreaction, nor by the same gradual weakening of the first and strengthening of the second. There must be a subset of aversive experiences that especially lend themselves to being overcome. The psychologist Paul Rozin has identified a syndrome of acquired tastes he calls benign masochism.260 These paradoxical pleasures include consuming hot chili peppers, strong cheese, and dry wine, and partaking in extreme experiences like saunas, skydiving, car racing, and rock climbing. All of them are adult tastes, in which a neophyte must overcome a first reaction of pain, disgust, or fear on the way to becoming a connoisseur. And all are acquired by controlling one’s exposure to the stressor in gradually increasing doses. What they have in common is a coupling of high potential gains (nutrition, medicinal benefits, speed, knowledge of new environments) with high potential dangers (poisoning, exposure, accidents). The pleasure in acquiring one of these tastes is the pleasure of pushing the outside of the envelope: of probing, in calibrated steps, how high, hot, strong, fast, or far one can go without bringing on disaster. The ultimate advantage is to open up beneficial regions in the space of local experiences that are closed off by default by innate fears and cautions. Benign masochism is an overshooting of this motive of mastery, and as Solomon and Baumeister point out, the revulsion-overcoming process can overshoot so far as to result in craving and addiction. In the case of sadism, the potential benefits are dominance, revenge, and sexual access, and the potential dangers are reprisals from the victim or victim’s allies. Sadists do become connoisseurs—the instruments of torture in medieval Europe, police interrogation centers, and the lairs of serial killers can be gruesomely sophisticated—and sometimes they can become addicts.
The fact that sadism is an acquired taste is both frightening and hopeful. As a pathway prepared by the motivational systems of the brain, sadism is an ever-present danger to individuals, security forces, or subcultures who take the first step and can proceed to greater depravity in secrecy. Yet it does have to be acquired, and if those first steps are blocked and the rest of the pathway bathed in sunlight, the path to sadism can be foreclosed.
IDEOLOGY
Individual people have no shortage of selfish motives for violence. But the really big body counts in history pile up when a large number of people carry out a motive that transcends any one of them: an ideology. Like predatory or instrumental violence, ideological violence is a means to an end. But with an ideology, the end is idealistic: a conception of the greater good.261
Yet for all that idealism, it’s ideology that drove many of the