High Price

harder they have to work for any reward—whether it’s a natural pleasure like food or sex or a more artificial one like drugs—the less of it they will tend to seek. This is true whether the animal being studied is a mouse, a rat, a monkey, or a human being. And both in humans and in other animals, these responses will vary depending on the presence of competing reinforcers.
    For example, studies have found that when rhesus monkeys have to repeatedly press levers to get either a cocaine injection or a highly desirable food (banana pellets), their responses vary with both effort and dose. Quite sensibly, the monkeys will work harder to get a higher dose of cocaine and put in less effort for a lower dose or placebo. They will also choose larger quantities of banana pellets over smaller doses of cocaine. Even at the highest dose of cocaine offered, these animals will never choose cocaine over banana pellets more than 50 percent of the time. 2 Addictive behavior follows rules and is shaped by situations just like other types of behavior. It’s not as weird or special as we make it out to be.
    You may say, “Yes, that’s fine with a drug like cocaine that doesn’t produce obvious withdrawal symptoms. But what about a drug like heroin?” Indeed, physical withdrawal symptoms can be seen in chronic opiate (for example, heroin, morphine) users if they abruptly stop drug use. The symptoms usually begin about twelve to sixteen hours after the last heroin dose and look something like a case of the twenty-four-hour, or intestinal, flu. Most of us have experienced these symptoms at some point in our lives: nausea, vomiting, diarrhea, aches, pains, and a general sense of misery. While this condition is most unpleasant, rarely is it life-threatening or accurately depicted in films that suggest the sufferer is on the verge of death.
    Throughout the 1960s, drug addiction was defined solely on the basis of the presence of physical dependence (a withdrawal syndrome). About that same time, a group of researchers began publishing findings that questioned this dominant view. They reported that: (1) monkeys would begin and maintain lever-pressing for opiates without first being made physically dependent; and (2) monkeys who had given themselves small amounts of a drug and who had never experienced withdrawal symptoms could be trained to work very hard for their opiate injections. 3 More recently, researchers have demonstrated that monkeys’ lever-pressings for heroin injections do not correspond with the timing or severity of their withdrawal symptoms. 4 These findings, along with others, underscore the notion that physical dependence isn’t the primary reason for continued drug use.
    I started to put these ideas together as I was trying to make my way in academia and dealing with a very unpredictable experience of reinforcers and punishers of my own. Although research careers are rarely presented this way when we are trying to attract youth to science, the reality is that the field is intensely competitive and many highly qualified people do not wind up with tenure-track jobs or even jobs in industry that take advantage of their skills. At UCSF and then even more so at Yale, I came face-to-face with the fierceness of this competition. It was extremely demoralizing at times.
    This fight for status was worse than what I’d seen on the street or on the basketball court, where it was at least clear when people were competing and what territory was in dispute. In academia, no one said anything to your face: it was all sneaky stuff, all easily denied or explained away as a “misunderstanding” or “miscommunication.” Men didn’t fight like men; they stabbed you in the back instead. The rules were actually clearer and easier to follow in the hood. But one of the true advantages of my background was that it made me sensitive to social signals, no matter where I encountered them. I was able to learn those used in academia and use them to win, even on such a convoluted playing field.
    Nonetheless, there were definitely times when I came close to giving up, when the low salary and grueling work hours with no guarantee of a definite payoff wore me down. The work at UCSF had been disillusioning: as James Baldwin had put it, when you learn a craft well, you get to see its ugly side, and that’s what happened to me, starting there. I felt that the research we were doing on craving was poorly conducted and not productive, that the link