With an advertisement in the Village Voice, Carl Hart invited addicts to earn $950 smoking crack made from pharmaceutical-grade cocaine in his lab at Columbia University. Hart, an associate professor of psychology, grew up in poverty in a black community and was no stranger to the effects crack has on its addicts.

According to an article in the New York Times, “Like other scientists, he hoped to find a neurological cure to addiction, some mechanism for blocking that dopamine activity in the brain so that people wouldn’t succumb to the otherwise irresistible craving for cocaine, heroin and other powerfully addictive drugs.”

When Hart began to study addicts, according to the Times, he realized that drugs like crack and meth were not impossible to resist as is commonly misconstrued.

Hart told the Times “80 to 90 percent of people who use crack and methamphetamine don’t get addicted…and the small number who do become addicted are nothing like the popular caricatures.”

Most of the respondents to Hart’s ad were black men from low-income neighborhoods like the one where Hart was raised in Miami. To participate in the study, they had to live in a hospital ward for a number of weeks while researchers watched from behind one-way mirrors.

As the Times reported, nurses administered “samples” of crack to the experimentees at the start of each day, then offered them additional crack samples throughout the day. An alternative offer was also made alongside each offer of crack. Participants could opt instead for a reward like $5 in cash or a $5 voucher to buy merchandise.

When the dose was high, the subject typically chose to continue smoking crack, but when the dose was lower they were more likely to trade it for $5.

Hart told the Times, “They didn’t fit the caricature of the drug addict who can’t stop once he gets a taste,” noting that the addicts were making “rational economic decisions.”

In an interview in June about his book High Price: A Neuroscientist's Journey of Self-Discovery That Challenges Everything You Know About Drugs and Society, Hart told AlterNet several false conclusions about “addictive” drugs were commonly drawn in America.

“There is a belief, for example, that crack cocaine is so addictive it only took one hit to get hooked, and that it is impossible to use heroin without becoming addicted,” he said. “There was another belief that methamphetamine users are cognitively impaired. All of these are myths that have have been perpetuated primarily by law enforcement, and law enforcement deals with a limited, select group of people—people who are, in many cases, behaving badly.”

Hart’s work to understand addiction and addicts tackles common misconceptions about several forms of drug addiction and addicts. He conducted similar studies around methamphetamine addicts in the past, as the Times article points out, and “found that when he raised the alternative reward to $20, every single addict, of meth and crack alike, chose the cash. They knew they wouldn’t receive it until the experiment ended weeks later, but they were still willing to pass up an immediate high.”

As Hart told AlterNet in June, his studies have shown that the pharmacological effects of drugs rarely lead to crime, “but the public conflates these issues regardless.”

“Certainly, we have given thousands of doses of crack cocaine and methamphetamine to people in our lab, and never had any problems with violence or anything like that,” he said. “That tells you it's not the pharmacology of the drug, but some interaction with the environment or environmental conditions, that would probably happen without the drug.”

The Times article notes that while some “drug warriors” doubt Hart, fellow scientists are convinced.

Craig R. Rush, a psychologist at the University of Kentucky told the Times that Hart’s argument is “persuasive.” In the same article, David Nutt, a British expert on drug abuse, said: “I have a great deal of sympathy with Carl’s views.… Addiction always has a social element, and this is magnified in societies with little in the way of work or other ways to find fulfillment.”

Hart said the reason people keep focusing on specific drugs as the root of greater societal problems is that they are “an easy scapegoat.” He says poverty in addition to bad policies—like placing large percentages of law enforcement in poor communities where they target the people most in need for petty crimes—is the real issue at play.

The Times article notes that, “It’s much simpler for politicians and journalists to focus on the evils of a drug than to grapple with the underlying social problems. But Dr. Hart also puts some of the blame on scientists.”

He told the Times: "We scientists know that we get more money if we keep telling Congress that we’re solving this terrible problem. We’ve played a less than honorable role in the war on drugs.”