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Correlation of Crime
Several different correlates of crime have been proposed with varying degrees of empirical support. The causes of crime are one of the major research areas in criminology. Yet, one needs to remember that correlation does not imply causation.
The Handbook of Crime Correlates (2009) is a systematic review of worldwide empirical studies on crime publicized in the academic literature. In order to identify well-established relationships to crime consistency scores were calculated for the factors which many studies have examined. The scoring depends on how consistent a statistically significant relationship was found in the studies. The authors argue that the review summaries most of what is currently known of variables associated with criminality.
Following is a concentration of relationships:
Biological
Age
Crime is most frequent in second and third decades of life.
Gender
Males commit more overall and violent crime. They also commit more property crime except shoplifting, which is about equally distributed between the genders. Males appear to be more likely to recidivate.
Arousal
Measures related to arousal such as heart rate and skin conductance are low among criminals.
Body type
Mesomorphic or muscular body type is positively correlated with criminality specifically of the sexual nature.
Hormones
Testosterone is positively correlated to criminality.
Biochemical markers
Low monoamines oxidize activity and low 5-HIAA levels are found among criminals.
Race, ethnicity and immigration
There is a relationship between race and crime.
Ethnically/racially diverse areas probably have higher crime rates compared to ethnically/racially homogeneous areas.
Most studies on immigrants have found higher rates of crime. However, this varies greatly depending on the country of origin with immigrants from some regions having lower crime rates than the indigenous population.
Early life
Pregnancy
Maternal smoking during pregnancy is associated with later criminality. Low birth weight and prenatal trauma/birth complications may be more prevalent among criminals.
Family
Child maltreatment, low parent-child attachment, marital discord/family discord, alcoholism and drug use in the family, and low parental supervision/monitoring are associated with criminality. Larger family size and later birth order are also associated.
Enuresis
Nocturnal enuresis or bed wetting correlates with criminality.
Bullying
Bullying is positively related to criminal behavior.
School
School disciplinary problems, truancy, low grade point average, and dropping out of high school are associated with criminality.
Lead Poisoning
Childhood lead exposure of a population correlates with criminal activity approximately twenty years later.
Alcohol and illegal drug use
High alcohol use, alcohol abuse, and alcoholism, as well as high illegal drug use and dependence are positively related to criminality in general.
Sex
Early age of first intercourse and more sexual partners are associated with criminality.
Friends
Few friends, criminal friends, and gang membership correlate positively with criminality.
Religion
On the individual level, most recent scientific studies have found a negative correlation between religiosity and criminality. A 2001 meta-analysis by Colin Baier and Bradley Wright found that, in general, "religious beliefs and behaviors exert a moderate deterrent effect on individuals' criminal behavior". An individual with high religious saliency (i.e. with high importance of religion to their life) is less likely to be associated with criminal activities; similarly, an individual who regularly attends religious services or is highly involved in them will be less involved in criminality, with the possible exception of property damage.
General morbidity
Criminals probably suffer from more illnesses.
Epilepsy
Epilepsy appears to have a positive correlation with criminality.
Accidental injuries
Criminals are more frequently accidentally injured.
Conduct disorder and antisocial personality disorder
Childhood conduct disorder and adult antisocial personality disorder are associated with one another and criminal behavior.
Attention deficit hyperactivity disorder
Attention deficit hyperactivity disorder correlates positively with criminality.
Depression and suicide
Minor depression and probably clinical depression is more likely among offenders. Depression in the family is associated with criminality. Criminals are more likely to be suicidal.
Schizophrenia
Schizophrenia and criminality appear to be positively correlated.
Intelligence quotient and learning disabilities
There is also a relationship between lower IQ and crime. A learning disability is a substantial discrepancy between IQ and academic performance. It has a relationship to criminal behavior. Slow reading development may be particularly relevant.
Personality traits
Several personality traits are associated with criminality: High impulsivity, high psychoticism, high sensation-seeking, high aggression in childhood, and low self control, low empathy and altruism.
Higher total socioeconomic status (usually measured using the three variables income (or wealth), occupational level, and years of education) correlate with less crime. Longer education is associated with less crime. Higher income/wealth have a somewhat inconsistent correlation with less crime with the exception of self-report illegal drug use for which there is no relation. Higher parental socioeconomic status probably has an inverse relationship with crime.
High frequency of changing jobs and high frequency of unemployment for a person correlate with criminality.
Somewhat inconsistent evidence indicates that there is a relationship between low incomes, percentage under the poverty line, few years of education, and high income inequality in an area and more crime in the area.
The relationship between the state of the economy and crime rates is inconsistent among the studies; also for differences in unemployment between different regions and crime rates. There is a slight tendency in the majority of the studies for higher unemployment rate to be positively associated with crime rates.
Cities or counties with larger populations have higher crime rates. Poorly maintained neighborhoods correlate with higher crime rates. High residential mobility is associated with a higher crime rate. More taverns and alcohol stores, as well as more gambling and tourist establishments, in an area are positively related to criminality.
There appears to be higher crime rates in the geographic regions of a country that are closer to the equator.
Crime rates vary with temperature depending on both short-term weather and season. The relationship between the hotter months of summer and a peak in rape and assault seems to be almost universal. For other crimes there are also seasonal or monthly patterns but they are more inconsistent across nations. On the other hand for climate, there is a higher crime rate in the southern US but this largely disappears after non-climatic factors are controlled for.
Risk of being a crime victim is highest for teens through mid 30s and lowest for the elderly. Fear of crime shows the opposite pattern. Criminals are more often crime victims. Females fear crimes more than males. Black Americans appear to fear crime more. Black people are more often victims, especially of murder.
Media depiction of violence
Media violence research examines whether links between consuming media violence and subsequent aggressive and violent behavior exists.
Gun politics
The effect of gun politics on crime is a controversial research area.
Drugs
Both legal and illegal drugs are implicated in drug-related crime.
Being an unwanted child
Children whose parents did not want to have a child are more likely to grow to be delinquents or commit crimes. Such children are also less likely to succeed in school, and are more likely to live in poverty. They also tend to have lower mother-child relationship quality. Children whose births were unintended are likely to be less mentally and physically healthy during childhood.
Biosocial criminology is an interdisciplinary field that aims to explain crime and antisocial behavior by exploring both biological factors and environmental factors. While contemporary criminology has been dominated by sociological theories, biosocial criminology also recognizes the potential contributions of fields such as genetics, neuropsychology, and evolutionary psychology.
The field of psychology has been greatly influenced by the study of genetics. Decades of research has demonstrated that both genetic and environmental factors play a role in a variety of behaviors in humans and animals (e.g. Grigorenko & Sternberg, 2003). The genetic basis of aggression, however, remains poorly understood. Aggression is a multi-dimensional concept, but it can be generally defined as behavior that inflicts pain or harm on another.
Genetic-developmental theory states that individual differences in a continuous phenotype result from the action of a large number of genes, each exerting an effect that works with environmental factors to produce the trait.[1]This type of trait is influenced by multiple factors making it more complex and difficult to study than a simple Mendelian trait (one gene for one phenotype).
Aggression, as well as other behavioral traits, is studied genetically based on its heritability through generations.
Heritability models of aggression are mainly based on animals due to the ethical concern in using humans for genetic study. Animals are first selectively bred and then placed in a variety of environmental conditions, allowing researchers to examine the differences of selection in the aggression of animals.
Research methods
As with other topics in behavioral genetics, aggression is studied in three main experimental ways to help identify what role genetics plays in the behavior:
These three main experimental types are used in animal studies, studies testing heritability and molecular genetics, and gene interaction/environment studies. Recently, important links between aggression and genetics have been studied and the results are allowing scientists to better understand the connections.
Selective breeding
The heritability of aggression has been observed in many animal strains after noting that some strains of birds, dogs, fish, and mice seem to be more aggressive than other strains. Selective breeding has demonstrated that it is possible to select for genes that lead to more aggressive behavior in animals.[7] Selective breeding examples also allow researchers to understand the importance of developmental timing for genetic influences on aggressive behavior. A study done in 1983 (Cairns) produced both highly aggressive male and female strains of mice dependent on certain developmental periods to have this more aggressive behavior expressed. These mice were not observed to be more aggressive during the early and later stages of their lives, but during certain periods of time (in their middle-age period) were more violent and aggressive in their attacks on other mice. Selective breeding is a quick way to select for specific traits and see those selected traits within a few generations of breeding. These characteristics make selective breeding an important tool in the study of genetics and aggressive behavior.
Experiments designed to study biological mechanisms are utilized when exploring how aggression is influenced by genetics. Molecular genetics studies allow many different types of behavioral traits to be examined by manipulating genes and studying the effect(s) of the manipulation.
Molecular genetics
A number of molecular genetics studies have focused on manipulating candidate aggression genes in mice and other animals to induce effects that can be possibly applied to humans. Most studies have focused on polymorphisms of serotonin receptors, dopamine receptors and neurotransmitter metabolizing enzymes. Results of these studies have led to linkage analysis to map the serotonin-related genes and impulsive aggression. In particular, the serotonin 5-HT seems to be an influence in inter-male aggression either directly or through other molecules that use the 5-HT pathway. 5-HT normally dampens aggression in animals and humans. Mice missing specific genes for 5-HT were observed to be more aggressive than normal mice and were more rapid and violent in their attacks. Other studies have been focused on neurotransmitters. Studies of a mutation in the neurotransmitter metabolizing enzyme monoamine oxidize A (MAO-A) have been shown to cause a syndrome that includes violence and impulsivity in humans. Studies of the molecular genetics pathways are leading to the production of pharmaceuticals to fix the pathway problems and hopefully show an observed change in aggressive behavior.
A rare genetic variant causing MAO-A deficiency has been associated with violent behavior in males. In 2002 a study published by researchers at King's College London found a link between a genetic variant causing low levels of MAO-A and increased levels of antisocial behavior in people who were mistreated as children. An American group studying monkeys called MAO-A a "warrior gene" in 2004. A 2008 study found a similar result involving the rare 2-repeat variant of the MAO-A gene, as well as the genes DAT1 and DRD2. In all three cases, the variants of these genes were associated with an elevated risk of violent and delinquent behavior only in people who experienced certain stresses during childhood.
Anthropological Criminology
Sometimes referred to as criminal anthropology, literally a combination of the study of the human species and the study of criminals) is a field of offender profiling, based on perceived links between the nature of a crime and the personality or physical appearance of the offender. Although similar to physiognomy and phrenology, the term criminal anthropology is generally reserved for the works of the Italian school of criminology of the late 19th century (Cesare Lombroso, Enrico Ferri, Raffaele Garofalo). Lombroso thought that criminals were born with inferior physiological differences which were detectable. He popularized the notion of "born criminal" and thought that criminality was an atavism or hereditary disposition. His central idea was to locate crime completely within the individual and utterly divorce it from the surrounding social conditions and structures. A founder of the Positivist school of criminology, Lombroso hereby opposed social positivism developed by the Chicago school and environmental criminology.
Biosocial criminology is an interdisciplinary field that aims to explain crime and antisocial behavior by exploring both biological factors and environmental factors. While contemporary criminology has been dominated by sociological theories, biosocial criminology also recognizes the potential contributions of fields such as genetics, neuropsychology, and evolutionary psychology.
Environment
Environment has a significant effect on genetic expression. Disadvantaged environments enhance antisocial gene expression, suppress prosocial gene action and prevent the realization of genetic potential.
Genes and environments operating in tandem (interacting) were required to produce significant antisocial behavior, while neither was powerful enough to produce it independent of the other. That is, children genetically at risk for antisocial behavior reared in positive family environments did not display antisocial behavior, and children not at genetic risk did not become antisocial in adverse family environments.
Genetics
One approach to studying the role of genetics for crime is to calculate the heritability coefficient, which describes the proportion of the variance that is due to actualized genetic effects for some trait in a given population in a specific environment at a specific time. The heritability coefficient for antisocial behavior is estimated to be between 0.40 and 0.58.
Neurophysiology
Another approach is to examine the relationship between neurophysiology and criminality. One example is that measured levels of neurotransmitters such as serotonin and dopamine have been associated with criminal behavior. Another is that neuro - imaging studies give strong evidence that both brain structure and function are involved in criminal behaviors. The limbic system creates emotions such as anger and jealousy that ultimately may cause criminal behavior. The prefrontal cortex is involved in delaying gratification and impulse control and moderates the impulses from the limbic system. If this balance is shifted in favor of the limbic system this may contribute to criminal behavior. Terrie Moffitt's developmental theory of crime argues that "life-course-persistent offenders" make up only 6% of the population but commits more than 50% of all crimes and that this is due to a combination neuro - physiological deficits and an adverse environment that creates a criminal path that is very difficult to break once started.
Evolutionary psychology
Men can potentially have many children with little effort; women only a few with great effort. This is argued to contribute to males having more variable reproductive success than females. One argued consequence of this is that males are more aggressive, and more violently aggressive, than females, since they face higher reproductive competition from their own sex than females. In particular, low-status males may be more likely to remain completely childless. Under such circumstances, it may be have evolutionarily useful to take very high risks and use violent aggression in order to try to increase status and reproductive success rather than become genetically extinct. This may explain why males have higher crime rates than females and why status and being unmarried low is associated with criminality. It may also explain why the degree of income inequality of a society is a better predictor than the absolute income level of the society for male-male homicides; income inequality creates social disparity, while differing average income levels may not do so. Furthermore, competition over females is argued to have been particularly intensive in late adolescence and young adulthood, which is theorized to explain why crime rates are particularly high during this period.
The "evolutionary neuro - androgenic theory" focuses on the hormone testosterone as a factor influencing aggression and criminality and being beneficial during certain forms of competition. In most species, males are more aggressive than females. Castration of males usually has a pacifying effect on aggressive behavior in males. In humans, males engage in crime and especially violent crime more than females. The involvement in crime usually rises in the early teens to mid teens in correlation with the rise of testosterone levels. Research on the relationship between testosterone and aggression is difficult since the only reliable measurement of brain testosterone is by lumbar puncture, which is not done for research purposes. Studies therefore have often instead used less reliable measurements from blood or saliva. Some studies support a link between adult criminality and testosterone, although the relationship is modest if examined separately for each sex. A significant link between juvenile delinquency and testosterone levels has not been established. Some studies have also found testosterone to be associated with behaviors or personality traits linked with criminality such as antisocial behavior and alcoholism. Many studies have also been done on the relationship between more general aggressive behavior/feelings and testosterone. About half the studies have found a relationship and about half no relationship.
Many conflicts causing homicides involve status conflicts, protecting reputation, and seemingly trivial insults.[2] Steven Pinker in his book The Blank Slate argues that in non-state societies without a police it was very important to have a credible deterrence against aggression. Therefore it was important to have a reputation for retaliation, causing humans to develop instincts for revenge as well as for protecting reputation ("honor"). Pinker argues that the development of