Andrews And Bonta (2010) Define
Andrews and Bonta (2010) define criminal behavior as behavior that is prohibited and punished by law, violating moral or religious code, violating norms of society or traditions, and causing serious psychological stress or mental damage to a victim (Andrews & Bonta, 2010). The study of crime, namely criminology, deals with the “nature, extent, causes, control, consequences, and prevention of criminal behavior” (Deflem, 2006). Its origin lies in the classical school of criminology, whose founding fathers, Cesare Beccaria and Jeremy Bentham, had proposed that people possess free will. Therefore, they argue that criminals actively chose to live a criminal life. This classical notion stands in contrast with the later emerging biological perspective of Cesare Lombroso.
During the nineteenth century, Cesare Lombroso studied criminals’ physical features and noticed that their bodies had some unusual, “atavistic” shapes, sizes, or characteristics. For example, large jaws and cheekbones reminded him of evolutionary earlier humans and therefore, in his view, an atavistic criminal had primitive traits that urged the individual to behave in a violent and criminal matter (Ellwood, 1912). A different but related biological theory was proposed in 1942 by William Sheldon. His constitutional psychology theory categorized individuals into three somato-(body-)types, namely endomorph, mesomorph, and ectomorph. Sheldon combined his somatotype classification with temperament types, which lead to the assumption that a certain body type was inherently more or less aggressive than another (Sheldon, 1963).
Lombroso’s and Sheldon’s theories were widely criticized, which lead to the complete ignorance of the biological perspective of criminology. Early biological theorists were unable to reach a sound explanation for the development of criminal behavior. Moreover, their findings were mostly irrational and simplistic due to their misuse of methodology and lack of knowledge about the brain. Furthermore, theorists were making singular causal implications that fueled the everlasting nature-nurture debate. This debate addresses the question whether human behavior is a product of nature (biology) or nurture (environment). The scientists’ purely biological point of view reminded of conservative political ideologies and movements such as radical behaviorism and social Darwinism, which contributed to the rejection of these biological perspectives.
Over the past few decades, there has fortunately been a great increase in technology available to study the human brain, which has led to a significantly deeper understanding and knowledge about the human body and behavior. Researchers have been able to provide feasible evidence to explain human phenomena by using research methods correctly to analyze and apply their findings. Contemporary biological theories of criminology have therefore emerged out of the dark and are accepted as sound explanations for human behavior (Fishbein, 1990). Thus, much additional research is conducted on the biological aspect of criminal behavior and this paper aims at giving insight into modern biological theories and at suggesting the most promising in terms of strong empirical support.
As biologically based criminological theories have reached wider acceptance among the field of criminology, multiple plausible theories have emerged and studies were conducted examining these and finding feasible results.
Quay, Hare, and later Eysenck in 1977 suggested that physiological under-arousal may be a biological characteristic of violent offenders (Quay, 1965; Hare, 1970; Eysenck, 1977). To examine these proposals, studies have been conducted on the psychophysical response system of criminals, which suggest that physiological under-arousal may be a common characteristic found in offenders. The psychophysical response system includes electro-dermal, cardiovascular, and cortical activity, which are related to physical arousal. One prospective study examined the resting skin conductance, heart rate, and electroencephalogram (EEG) activity, first on 15-year old boys, and later the same boys at the age of 24 to compare their criminal or non-criminal behavior with their biological disposition to have a high or low baseline arousal state. Criminal offenders had a significantly lower resting heart rate, reduced skin conductance activity, and a slower EEG theta activity (compared to non-criminals). Their findings provided evidence that criminal’s arousal system is lower than that of non-criminals, as the measures correctly identified criminals and non-criminals in 75 % of the cases. Additionally, it was found that aggressive children had a lower resting heart rate at 3 years of age (compared to non-aggressive children) (Reine, Venables, & Williams, 1990; Fishbein, 1990).
In addition to the under-arousal theory, a stimulation-seeking theory has been suggested to explain criminal behavior. It suggests that criminals have a low physical arousal baseline, and theorists propose that individuals are driven to robbery, theft, violence, and other types of crimes to obtain an increased arousal, compensating for their biological disposition to have a low arousal base-line compared to the norm (Quay, 1965; Eysenck, 1977). Alternatively, a fearlessness theory points out that the low physical arousal (e.g. low resting heart rate) might index fearlessness, which may prone individuals to become involved in crimes such as robbery because they are not afraid of being hurt, getting caught, or of the legal consequences.
As arousal is partly regulated by the frontal lobe, theories have proposed that individuals with damage or dysfunction to the frontal lobe may be predisposed to violent and delinquent behavior (Hellige, 1993). A brain imaging study conducted by Raine, et al. (1994) assessed glucose metabolism using positron emission tomography (PET) in murderers, which were proven to be characterized by reduced glucose metabolism exclusively in the pre-frontal brain region. Therefore, this frontal dysfunction could indicate a predisposition to violence, as the reduced functioning in the pre-frontal cortex could result in reduced inhibition on brain regions facilitating aggression (Gorenshein & Newman, 1980). Additionally, pre-frontal damage or dysfunction may lead to intellectual, behavioral, and personality related changes including risky, rule-breaking, impulsive, immature behavior as well as, poor social judgement, poor concentration, and loss of problem-solving skills. These difficulties may result in low social abilities, academic and employment failure, and aggressive tendencies, which could lead a criminal life style and predisposing the individual to delinquent behavior (Kolb & Wishaw, 1990). It is important to mention that this hypothesis requires environmental and social considerations.
Advances in neuroscience have fueled researchers to examine genetic effects in the brain relating to violent and criminal behavior. Functional polymorphisms in the dopaminergic system have been found to be associated with antisocial behavior. The dopaminergic system encompasses frontal regions of the brain, including the pre-frontal cortex. Dopamine levels facilitate addictive and reward seeking behavior, and pathological behaviors such as gambling, novelty seeking, and addiction are examples of these antisocial behaviors. DRD2 and DRD4 are genes that encode dopamine receptors D2 and D4, therefore influencing levels of dopamine in the brain. Research provided evidence that both genes interact to increase the probability of aggressive and criminal behavior (Beaver, et al., 2007; Boutwell, et al., 2014).
Genetic effects are not only studied by studying the brain, but also by comparing monozygotic (identical) and dizygotic (fraternal) twins. As monozygotic twins share 100 percent of their genes in comparison to fraternal twins, who only share 50 percent, one can conclude that similarities and/or differences of the twins within each pair compared to the twins between each pair will be due to the heritability of that phenotype (Raine, 2002). Multiple twin studies over time have shown greater similarity rates of criminal behavior for monozygotic twins (compared to dizygotic twins) (Raine, 1993). Limitations on twin studies stressing the fact that dizygotic twins may share a greater amount of common environment have been discredited by Grove (1990), who conducted a study with twins that were reared apart. He found a significant similarity between criminality and the shared genes of monozygotic twins.
An additional form of studying the genetic component of human phenomena is by using a 2 x 2 design of comparing adopted children reared apart from their either criminal or non-criminal biological parent to an either criminal or non-criminal foster parent. Studies using this design have found significant evidence for the genetic component of criminal behavior, as children with criminal biological parents had more criminal records than those of non-biological parents (Mednick, 1987).
Nevertheless, the most significant findings are found when taking genetic, as well as environmental factors into account. Cloninger et al. (1982) conducted a study in which he separated adopted children into four groups, depending on the presence of a genetic risk for criminality, an environmental risk for criminality, or a combination of both. Results showing a significantly higher criminality rate for adoptees with both genetic and environmental risk factors in comparison to single risk factors prove that genes and environment interact.
The interaction of environemental and social factors with biological and genetic factors becomes evident in many studies concerning the biological approach of criminal behavior when the environment is also considered. Birth complications, for example, result in brain dysfunctions that alone may predispose to violence as they are linked to later antisocial behavior (Raine, 1993), but studies show that prenatal complications (e.g. nicotine, alcohol, and drug exposure, nutrition deficits and metal toxicity, and brain damage (Liu & Wuerker, 2005)) in combination with a negative psychosocial environment provides stronger evidence for the association with violent behavior (Raine, et al., 1994). Further evidence has emerged that negative psychosocial environments such as child neglect, lack of maternal warmth, and separation from parents may predispose individuals toward violent crime (Farrington, 1991). Poor mother-infant bonding may lead to more careless and affectionless interpersonal relationships, which might increase the likelihood of violent interpersonal behavior. Bowlby’s attachment theory is primarily concerned with the innate and evolutionary instinct to from a bond in the early stages of life with one’s caregiver. This bond will then later be the basis of one’s personality, behavior, and further relationships (Bowlby, 1949).