In 1989, President George H.W. Bush appeared on national television to address the country’s drug problem. As a means of demonstrating how widespread drug abuse had become, he held up a bag of crack cocaine that the DEA purposefully arranged to purchase in Lafayette Park across from the White House. “It is innocent looking as candy,” the President intoned, “but it is turning our cities into battle zones, and it is murdering our children. Let there be no mistake, this stuff is poison.”

For most of the 1980s and 1990s, drugs were portrayed as the driving force behind high crime rates, lack of educational achievement, and urban decay. Government propaganda during that time period consistently portrayed drug users more or less as zombies held in thrall to an addictive substance, against which they were powerless.

But, according to Columbia University neuroscientist Carl Hart, this is abject nonsense. In his new book High Price, Hart deftly combines his autobiography with his laboratory research into drug use to call into question the government line on drugs. Either aspect of the book would have been interesting enough on its own merits, but the almost seamless combination of the personal and the academic makes the book greater than the sum of its parts.

Hart is the first black tenured professor of sciences at Columbia, and that is all the more remarkable considering his unlikely path to the Ivy League. He grew up in Miami in the 1970s, and his immediate family was broken apart when Hart was seven, as a result of his father’s infidelity and domestic abuse of his mother. That split forced Carl and his siblings to live with either one parent or a rotating cast of aunts and grandparents. By the time he was a sophomore, Hart’s family was living in the projects, and he was just scraping through school.

As he tells his life story, Hart carefully considers the choices that allowed him to beat the odds and contextualizes them with psychological research. He acknowledges in many cases that he made positive choices mostly out of chance.

For instance, Hart excelled in sports as an adolescent, and his desire to compete ensured that he kept at least the minimum GPA. However, he was relatively short for a basketball player, so he was not recruited to play collegiately. Then Hart took the Armed Services Vocational Aptitude Battery, almost purely to avoid going to class the day the test was offered, but he ended up scoring well enough to gain entry into the Air Force. By enlisting, Hart was able to travel to both Japan and England and begin taking college courses.

On his first visit home from the Air Force over Christmas 1984, Hart started to hear more people in his old neighborhood talking about freebasing cocaine. In particular, he recalls a story about an acquaintance named Ronnie who owned a customized Monte Carlo that friends said had gone “in the pipe.” Over the next few years, Carl observed the “crack epidemic” explode across America from his posts abroad, and his desire to do something about the drug problem is part of what motivated him to pursue his undergraduate degree in psychology after leaving the Air Force.

However, as he moved on to graduate school, he began to question the prevailing view of drug addiction. Most scientists at the time endorsed the “dopamine hypothesis of addiction,” in which drugs that increase the amount of the neurotransmitter dopamine force addicts to constantly seek out this chemical reward.

Hart soon found that this simplistic, mechanical explanation for drug addiction was used to explain contradictory findings. Mice will self-administer cocaine, and if they are given a drug that blocks dopamine, they will initially respond even more before giving up entirely. On the other hand, rats given nicotine will stop responding immediately if the dopamine signal is blocked. Yet many researchers continued to proffer the dopamine hypothesis as an explanation for both responses.

Hart became interested in observing the use of illicit drugs in a controlled, laboratory setting. “It seemed to me,” Hart writes, “that it would be much more useful to study people’s actual decisions about whether to take drugs, rather than focus so much on what they said they wanted or craved in some hypothetical future.” What he discovered was that “[a]ddictive 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.”

When Hart was first hired for a postdoctoral stint at Columbia, he designed an experiment in which frequent cocaine users were given a dose of cocaine of varying strengths or a placebo, and then asked to choose between the same dose or vouchers for merchandise or cash. Not surprisingly, stronger doses of cocaine made participants more likely to choose the drug, which is consistent with the traditional, biologically deterministic view of addiction. However, participants were also less likely to choose the drug if offered $5 in cash instead of a voucher, and when the cash amount increased to $20, almost no participants chose the cocaine.

“Like the rest of us,” Hart argues, “people who are addicted to crack cocaine are sensitive not only to one type of pleasure but also to many. While severe addiction may narrow people’s focus and reduce their ability to take pleasure in nondrug experiences, it does not turn them into people who cannot react to a variety of incentives.”

Although Hart does not explore the connection, his results are consistent with the “rational addiction hypothesis” first put forward by economists Kevin Murphy and the recently-deceased Nobel Laureate Gary Becker in 1988. Under this view, drug addicts are not acting irrationally; they are maximizing their utility and will reduce their drug consumption if the price increases or will increase in the future.

How then does Hart explain the dire conditions in which the stereotypical drug addict lives? He argues that those dire conditions are more often the cause of drug addiction than the result.

A key problem is that poor people actually have few ‘competing reinforcers.’ Crack isn’t really all that overwhelmingly good or superpowerfully reinforcing: it gained the popularity that it achieved in the hood … because there weren’t that many other affordable sources of pleasure and purpose and because many of the people at the highest risk had other preexisting mental illnesses that affected their choices.

In other words, America’s drug problem is not primarily about drugs. Instead drug abuse is a symptom of a variety of other social problems, and, not surprisingly, those problems are worst in the poorest communities.

Hart stops short of calling for full legalization of all drugs, but he does recommend the decriminalization of drug possession. Portugal decriminalized drug possession in 2001 and has seen declines in drug-induced deaths and rates of drug use, particularly among the youth. “Portuguese continue to get high, just like their contemporaries and all human societies before them. But they don’t seem to have the problem of stigmatizing, marginalizing, and incarcerating substantial proportions of their citizens for minor drug violations.”

Refreshingly, Hart does not peddle any panaceas. His biography and research show drug abuse and the other social problems associated with it to be complex phenomena that will not be remedied or even ameliorated by simplistic solutions. However, Hart has at least demonstrated how we can begin to understand and substantively address those problems, instead of naively scapegoating certain politically convenient chemicals for all of society’s ills.

John Payne is the executive director of Show-Me Cannabis and lives in St. Louis, Missouri.