In prisons around the world, inmates often wield a striking amount of authority and control. Research by Sacha Darke, for example, documents how some Brazilian jails have been administered almost entirely by the prisoners. Prisoners maintain the facility, distribute clothing and food, and ensure the security of the prison — even going so far as to handcuff and escort inmates during visit times, conducting strip searches, and completing the evening head count. In Bolivia, and many other parts of Latin America, prisoners themselves play a central role in bringing in necessities, like food, water, and health care supplies. However, this phenomenon is not limited to countries in Latin America. In fact, prison gangs play a similar role today, even in many facilities across the United States.

In my book, The Social Order of the Underworld: How Prison Gangs Govern the American Penal System, I argue that the size of the prison population — and especially the growth in the size of prisons — are crucial factors in explaining when and where gangs dominate prison. For more than 100 years, there were no prison gangs in the California prison system, but today they have a tremendous influence on nearly every aspect of an inmate’s life.

Prior to the 1960s, prisoners in California organized their daily lives around the Convict Code. It was an informal norm about what was considered acceptable behavior when interacting with other prisoners:

  • Don’t snitch.
  • Don’t steal.
  • Don’t lie.
  • Pay your debts.
  • Do your own time.

If you followed the Code, you had high social status and the support of your peers. You were relatively safe from victimization. If you violated the Code, you were ostracized and therefore in danger. The Code provided order because people cared about their reputations and other prisoners could know who was upstanding and who was not.

Why did the Convict Code fail?

While the Code governed effectively for many years, it eventually failed. The informal system could only work when prisoners knew other people’s reputations. However, the ability to know this information is only possible in relatively small prisons and small prison systems. The total state prison population from its founding in 1851 through 1950 was always fewer than 10,000 prisoners.

After that, there is a notable increase in the prison population through the 1960s. This initial increase is then subsequently dwarfed by the dramatic increase during the 1980s prison boom. To accommodate this growth, the number of state prisons in California increased from four in 1945 to 35 facilities today. In short, there are massively more prisoners, churning through more facilities, each one of which holds far more people. As a result, there is no way that a prisoner can know most of the people with whom he will interact.

As the prison populations boomed, California prisons saw increasing rates of inmate-on-inmate violence, stabbings, and large-scale rioting. This is evidence that the Code was failing to provide order.

What do gangs have to offer inmates in large prisons?

In this increasingly unstable and vulnerable environment, prisoners created gangs for protection. The 1960s witnessed the creation of notorious groups like the Aryan Brotherhood, Mexican Mafia, and Nuestra Familia prison gangs. Even though we often think of gangs as sources of disorder, prison gangs today are actually a crucial source of order and stability. They govern a vast number of social and economic interactions among prisoners.

Prison gangs are distinct from other forms of prison social order or hierarchy. I define them as prisoner-created groups that operate in the prison, whose membership is restrictive (there are requirements for joining), mutually exclusive (you can’t be in more than one gang), and have permanence (often a lifetime commitment).

Prison gangs govern through a community responsibility system: each member of the gang is responsible for the actions of all other members. For instance, if one member reneges on a debt, all are responsible for its repayment. Gang leaders can know, monitor, and control their own members at much lower cost than can strangers. Group responsibility provides assurance to other prisoners that someone will be held accountable in their dealings.

This structure governs social conflict (such as when a prisoner feels disrespected), violations of one’s property (such as theft), physical harm, and perhaps most importantly, dealings in the underground economy. The illicit nature of the trade in contraband means that prisoners cannot rely on officials to resolve disputes. As a result, prison gangs now serve as a quasi-legal system to adjudicate illicit commercial disputes.

Why do prisoners rely on gangs?

There are several reasons why prison gangs are the more efficient provider of order in large prison populations. First, they have written rules that they distribute to newly arriving prisoners. One gang in the Los Angeles County Jail, for example, hands out a list of 28 rules for prisoners to follow. Second, the gangs are cohesive internally because they rely on written constitutions. These often outline elaborate systems of checks and balances, complaint procedures, and elections. Third, they maintain detailed records of people who have violated gang rules and deserve to be fined or assaulted. Fear of landing on this list encourages compliance by prisoners.

Finally, gangs often administer extensive questionnaires to new inmates, which ask about a prisoner’s rap sheet, criminal involvement, street gang affiliation, and past prison stays. These result in a quasi-bureaucratic organization with the information and ability to create and enforce rules in large prison populations.

My basic claim is that prison gangs emerge in large prison populations when prisoners cannot rely on informal norms to provide order. This theory seems to explain well the history of California. It is also consistent with observations of prisons outside of California. For example, U.S. state prison systems that are much smaller (such as Vermont and Wyoming) have less serious prison gang problems; California and Texas are the two largest systems and have some of the most entrenched prison gangs.

Likewise, prisoners in England and Wales tend to rely on informal mechanisms that resemble the Convict Code system, instead of on highly organized prison gangs. However, the average prison size in England and Wales is only about 700 people, compared to California, where it is nearly 3,500 people. In other words, the average population in a California prison is five times the size of one in England and Wales. Not surprisingly, the Scandinavian prisons are much smaller on average, and they do not have a prison gang problem like the one in California. (My current research investigates these international differences in prison social order.)

What can be done to reduce prison gang power?

It’s crucial to note that even if prison gangs provide some order and stability in California, they are far from the ideal of how prisons should be administered. Gangs lack robust systems of accountability. They do not treat all prisoners equally. By developing a criminal form of social capital and requiring a lifetime commitment from members, they undermine rehabilitation and increase the likelihood of a person returning to prison. They wield violence to get their way. Therefore, it is crucial to understand why they come to power and to take steps to prevent them from doing so.

How can officials reduce the influence of prison gangs? First, if prisoners turn to gangs for security, officials should make prisons safer. One way to do that is to make them smaller. Prison staff members often claim it is easier to monitor and control prisoners in small facilities. Likewise, prisoners themselves find it easier to rely on informal norms like the Convict Code in small facilities because they can more easily know others’ reputations.

Second, if prisoners turn to gangs to facilitate the underground economy, officials should consider ways to liberalize the prison economy. For example, California banned cigarettes in prisons (for public health reasons), but now gangs earn thousands of dollars by trafficking them into the prisons. Similarly, phone calls are notoriously expensive, so many prisoners are eager to find alternatives, such as contraband cell phones. Gangs earn money and power by meeting these needs in the marketplace.

For a stark contrast, consider prison practices in Scandinavian countries. Prisoners have far better access to food, clothing, health care, and other amenities. As a result, there is much less illicit economic activity taking place in the prisons. In fact, research shows that even in opiate treatment facilities, where officials provide the drugs, there are no significant underground drug markets. The lesson that we should take from these examples is that when prison officials ban a desired good, it creates a profit opportunity for entrepreneurial prison gangs.

Gangs do not exist because inmates are inherently violent, pathological, or irrational. That’s why segregating gang leaders in places like California’s maximum-security prison in Pelican Bay has not stopped the gangs. Other prisoners still have a strong financial incentive to fill the void. Gangs arise because inmates have a demand for what they provide: security, order, and contraband. Therefore, to undermine gangs, officials need to meet the needs for which prisoners turn to them. One way of doing so is to make prisons smaller and safer.

A version of this article appeared at Penal Reform International.