13 minute read

Causes of Crime - Explaining Crime, Physical Abnormalities, Psychological Disorders, Social And Economic Factors, Broken Windows, Income And Education

Law Library - American Law and Legal InformationCrime and Criminal Law

How do some people decide to commit a crime? Do they think about the benefits and the risks? Why do some people commit crimes regardless of the consequences? Why do others never commit a crime, no matter how desperate their circumstances? Criminology is the study of crime and criminals by specialists called criminologists. Criminologists study what causes crime and how it might be prevented.

Throughout history people have tried to explain what causes abnormal social behavior, including crime. Efforts to control "bad" behavior go back to ancient Babylon's Code of Hammurabi some 3,700 years ago. Later in the seventeenth century European colonists in North America considered crime and sin the same thing. They believed evil spirits possessed those who did not conform to social norms or follow rules. To maintain social order in the settlements, persons who exhibited antisocial behavior had to be dealt with swiftly and often harshly.

By the twenty-first century criminologists looked to a wide range of factors to explain why a person would commit crimes. These included biological, psychological, social, and economic Throughout history people have tried to explain why a person would commit crimes. Some consider a life of crime better than a regular job—at least until they are caught. (© Bettmann/Corbis) factors. Usually a combination of these factors is behind a person who commits a crime.

Reasons for committing a crime include greed, anger, jealously, revenge, or pride. Some people decide to commit a crime and carefully plan everything in advance to increase gain and decrease risk. These people are making choices about their behavior; some even consider a life of crime better than a regular job—believing crime brings in greater rewards, admiration, and excitement—at least until they are caught. Others get an adrenaline rush when successfully carrying out a dangerous crime. Others commit crimes on impulse, out of rage or fear.

The desire for material gain (money or expensive belongings) leads to property crimes such as robberies, burglaries, white-collar crimes, and auto thefts. The desire for control, revenge, or power leads to violent crimes such as murders, assaults, and rapes. These violent crimes usually occur on impulse or the spur of the moment when emotions run high. Property crimes are usually planned in advance.

Discouraging the choice of crime

The purpose of punishment is to discourage a person from committing a crime. Punishment is supposed to make criminal behavior less attractive and more risky. Imprisonment and loss of income is a major hardship to many people. Another way of influencing choice is to make crime more difficult or to reduce the opportunities. This can be as simple as better lighting, locking bars on auto steering wheels, the presence of guard dogs, or high technology improvements such as security systems and photographs on credit cards.

A person weighing the risks of crime considers factors like how many police officers are in sight where the crime will take place. Studies of New York City records between 1970 and 1999 showed that as the police force in the city grew, less crime was committed. A change in a city's police force, however, is usually tied to its economic health. Normally as unemployment rises, city revenues decrease because fewer people are paying taxes. This causes cutbacks in city services including the police force. So a rise in criminal activity may not be due to fewer police, but rather rising unemployment.

Home security consultant conferring with client. Security systems and guard dogs can make crime more difficult or reduce the opportunities for it to occur. (Ms. Martha Tabor/Working Images Photographs)

Another means of discouraging people from choosing criminal activity is the length of imprisonment. After the 1960s many believed more prisons and longer sentences would deter crime. Despite the dramatic increase in number of prisons and imposing mandatory lengthy sentences, however, the number of crimes continued to rise. The number of violent crimes doubled from 1970 to 1998. Property crimes rose from 7.4 million to 11 million, while the number of people placed in state and federal prisons grew from 290,000 in 1977 to over 1.2 million in 1998. Apparently longer prison sentences had little effect on discouraging criminal behavior.

Parental relations

Cleckley's ideas on sociopathy were adopted in the 1980s to describe a "cycle of violence" or pattern found in family histories. A "cycle of violence" is where people who grow up with abuse or antisocial behavior in the home will be much more likely to mistreat their own children, who in turn will often follow the same pattern.

Children who are neglected or abused are more likely to commit crimes later in life than others. Similarly, sexual abuse in childhood often leads these victims to become sexual predators as adults. Many inmates on death row have histories of some kind of severe abuse. The neglect and abuse of children often progresses through several generations. The cycle of abuse, crime, and sociopathy keeps repeating itself.

Children who are neglected or abused commit substantially more crimes later in life than others. (© Roy Morsch/Corbis)

The cycle of violence concept, based on the quality of early life relationships, has its positive counterpart. Supportive and loving parents who respond to the basic needs of their child instill self-confidence and an interest in social environments. These children are generally well-adjusted in relating to others and are far less likely to commit crimes.

By the late twentieth century the general public had not accepted that criminal behavior is a psychological disorder but rather a willful action. The public cry for more prisons and tougher sentences outweighed rehabilitation and the treatment of criminals. Researchers in the twenty-first century, however, continued to look at psychological stress as a driving force behind some crimes.

Heredity and brain activity

Searching for the origins of antisocial personality disorders and their influence over crime led to studies of twins and adopted children in the 1980s. Identical twins have the exact same genetic makeup. Researchers found that identical twins were twice as likely to have similar criminal behavior than fraternal twins who have similar but not identical genes, just like any two siblings. Other research indicated that adopted children had greater similarities of crime rates to their biological parents than to their adoptive parents. These studies suggested a genetic basis for some criminal behavior.

Prisoner in California being prepared for a lobotomy in 1961. At the time, many psychiatrists believed that criminal behavior was lodged in certain parts of the brain, and lobotomies were frequently done on prisoners. (© Ted Streshinsky/Corbis)

With new advances in medical technology, the search for biological causes of criminal behavior became more sophisticated. In 1986 psychologist Robert Hare identified a connection between certain brain activity and antisocial behavior. He found that criminals experienced less brain reaction to dangerous situations than most people. Such a brain function, he believed, could lead to greater risk-taking in life, with some criminals not fearing punishment as much as others.

Studies related to brain activity and crime continued into the early twenty-first century. Testing with advanced instruments probed the inner workings of the brain. With techniques called computerized tomography (CT scans), magnetic resonance imaging (MRI), and positron emission tomography (PET), researchers searched for links between brain activity and a tendency to commit crime. Each of these tests can reveal brain activity.

Research on brain activity investigated the role of neurochemicals, substances the brain releases to trigger body activity, and hormones in influencing criminal behavior. Studies indicated that increased levels of some neurochemicals, such as serotonin, decreases aggression. Serotonin is a substance produced by the central nervous system that has broad sweeping effects on the emotional state of the individual. In contrast higher levels of others, such as dopamine, increased aggression. Dopamine is produced by the brain and affects heart rate and blood pressure. Researchers expected to find that persons who committed violent crimes have reduced levels of serotonin and higher levels of dopamine. This condition would have led to periods of greater activity including aggression if the person is prone towards aggression.

In the early twenty-first century researchers continued investigating the relationship between neurochemicals and antisocial behavior, yet connections proved complicated. Studies showed, for example, that even body size could influence the effects of neurochemicals and behavior.


Hormones are bodily substances that affect how organs in the body function. Researchers also looked at the relationship between hormones, such as testosterone and cortisol, and criminal behavior. Testosterone is a sex hormone produced by male sexual organs that cause development of masculine body traits. Cortisol is a hormone produced by adrenal glands located next to the kidneys that effects how quickly food is processed by the digestive system. Higher cortisol levels leads to more glucose to the brain for greater energy, such as in times of stress or danger. Animal studies showed a strong link between high levels of testosterone and aggressive behavior. Testosterone measurements in prison populations also showed relatively high levels in the inmates as compared to the U.S. adult male population in general.

Studies of sex offenders in Germany showed that those who were treated to remove testosterone as part of their sentencing became repeat offenders only 3 percent of the time. This rate was in stark contrast to the usual 46 percent repeat rate. These and similar studies indicate testosterone can have a strong bearing on criminal behavior.

Cortisol is another hormone linked to criminal behavior. Research suggested that when the cortisol level is high a person's attention is sharp and he or she is physically active. In contrast, researchers found low levels of cortisol were associated with short attention spans, lower activity levels, and often linked to antisocial behavior including crime. Studies of violent adults have shown lower levels of cortisol; some believe this low level serves to numb an offender to the usual fear associated with committing a crime and possibly getting caught.

It is difficult to isolate brain activity from social and psychological factors, as well as the effects of substance abuse, parental relations, and education. Yet since some criminals are driven by factors largely out of their control, punishment will not be an effective deterrent. Help and treatment become the primary responses.


Conforming to Merton's earlier sociological theories, a survey of inmates in state prisons in the late 1990s showed very low education levels. Many could not read or write above elementary school levels, if at all. The most common crimes committed by these inmates were robbery, burglary, automobile theft, drug trafficking, and shoplifting. Because of their poor educational backgrounds, their employment histories consisted of mostly low wage jobs with frequent periods of unemployment.

Employment at minimum wage or below living wage does not help deter criminal activity. Even with government social services, such as public housing, food stamps, and medical care, the income of a minimum wage household still falls short of providing basic needs. People must make a choice between continued long-term low income and the prospect of profitable crime. Gaining further education, of course, is another option, but classes can be expensive and time consuming. While education can provide the chance to get a better job, it does not always overcome the effects of abuse, poverty, or other limiting factors.

Peer influence

A person's peer group strongly influences a decision to commit crime. For example, young boys and girls who do not fit into expected standards of academic achievement or participate in sports or social programs can sometimes become Crack cocaine pipe displayed by police. Drugs and alcohol impair judgment and reduce inhibitions, giving a person greater courage to commit a crime. (© Bettmann/Corbis) lost in the competition. Children of families who cannot afford adequate clothing or school supplies can also fall into the same trap. Researchers believe these youth may abandon schoolmates in favor of criminal gangs, since membership in a gang earns respect and status in a different manner. In gangs, antisocial behavior and criminal activity earns respect and street credibility.

Like society in general, criminal gangs are usually focused on material gain. Gangs, however, resort to extortion, fraud, and theft as a means of achieving it. The fear of young people, mostly boys, joining gangs influenced many government projects in the last half of the twentieth century including President Lyndon Johnson's (1908–1973; served 1963–69) "War on Crime" programs.

Drugs and alcohol

Some social factors pose an especially strong influence over a person's ability to make choices. Drug and alcohol abuse is one such factor. The urge to commit crime to support a drug habit definitely influences the decision process. Both drugs and alcohol impair judgment and reduce inhibitions (socially defined rules of behavior), giving a person greater courage to commit a crime. Deterrents such as long prison sentences have little meaning when a person is high or drunk.

Substance abuse, commonly involving alcohol, triggers "stranger violence," a crime in which the victim has no relationship whatsoever with his or her attacker. Such an occurrence could involve a confrontation in a bar or some other public place where the attacker and victim happen to be at the same time. Criminologists estimate that alcohol or drug use by the attacker is behind 30 to 50 percent of violent crime, such as murder, sexual assault, and robbery. In addition drugs or alcohol may make the victim a more vulnerable target for a criminal by being less attentive to activities around and perhaps visiting a poorly lighted or secluded area not normally frequented perhaps to purchase drugs.

The idea that drug and alcohol abuse can be a major factor in a person's life is why there are numerous treatment programs for young people addicted to these substances. Treatment focuses on positive support to influence a person's future decision making and to reduce the tendency for antisocial and criminal behavior.

Easy access

Another factor many criminologists consider key to making a life of crime easier is the availability of handguns in U.S. society. Many firearms used in crimes are stolen or purchased illegally (bought on what is called the "black market"). Firearms provide a simple means of committing a crime while allowing offenders some distance or detachment from their victims. Of the 400,000 violent crimes involving firearms in 1998, over 330,000 involved handguns. By the beginning of the twenty-first century firearm use was the eighth leading cause of death in the United States.

Similarly, the increased availability of free information on the Internet also makes it easy to commit certain kinds of At the beginning of the twenty-first century, firearm use was the eighth leading cause of death in the United States. (AP/Wide World Photos) crime. Web sites provide instructions on how to make bombs and buy poisons; all this information is easily available from the comfort of a person's home. Easy access, however, will not be the primary factor in a person's decision to commit a crime. Other factors—biological, psychological, or social—will also come into play.

For More Information


Arrigo, Bruce A., ed. Social Justice, Criminal Justice. Belmont, CA: Wadsworth, 1999.

Bowlby, John. A Secure Base: Parent-Child Attachment and Healthy Human Development. New York: Basic Books, 1988.

Cleckely, Hervey. The Mask of Sanity. New York: New American Library, 1982.

Cohen, Albert K. Delinquent Boys: The Culture of the Gang. New York: Free Press, 1955.

Curran, Daniel J., and Claire M. Renzetti. Theories of Crime. Boston, MA: Allyn & Bacon, 2001.

Fleisher, Mark S. Beggars and Thieves: Lives of Urban Street Criminals. Madison, WI: University of Wisconsin Press, 1995.

Karr-Morse, Robin, and Meredith S. Wiley. Ghosts from the Nursery: Tracing the Roots of Violence. New York: Atlantic Monthly Press, 1997.

Lombroso, Cesare. Crime: Its Causes and Remedies. Montclair, NJ: Patterson Smith, 1968.

Renzetti, Claire M., and Lynne Goodstein, eds. Women, Crime, and Criminal Justice. Los Angeles: Roxbury, 2001.

Web Site

Criminal Justice. http://www.wadsworth.com/criminaljustice_d/ (accessed on August 19, 2004).

Additional topics