During the 19th century the concept of an influence of the biological factors on criminal behaviour was strong, due to Charles Darwin publications of the theory of evolution. However, when considering criminological issues, biological and psychological explanations have been rejected for some time. It is worth noting, that in recent times there has been an increasing interest in studying the relationships of biological and psychological factors and criminal behaviour. (Lilly et al, 2007; 20)
According to Reid (2006), there is no doubt, that the biological and social factors, especially their interactions are important in understanding and explaining the causes of criminal behaviour.
Cesare Lombroso (1835-1909), Italian psychiatrist and anthropologist , is considered today as a father of modern criminology. During his research about criminals, Lombroso relied on a Darwin’s theory of evolution, to support his own theory, that criminals had not evolved as far as non-criminals. Furthermore, Lombroso compared criminals to wild creatures, who like their wild predecessors, had many atavistic traits, which made them more likely to behave like a wild animals. That was the reason, that Lombroso famously claimed that he had found the biological characteristics, which allows to distinguish criminals according to crimes committed by them. Consequently rapists were characterized by short-handed, narrow forehead, often blonde hair, abnormalities of the nose and in the genital organs area. Lombroso believed that repeat offenders are among those that may be considered “criminals by birth”, so the two types of criminals were distinguished as a result of his studies about the criminal behavior. These were criminaloid and insane criminal. According to Lombroso’s findings, criminaloid is a person, who is motivated by passion, what with other factors lead to criminal behavior. On the other hand there is an insane criminal, who is epileptic, psychotic, unfit to society, who cannot control his behavior.(Lilly et al, 2007;18-24; Einstadter 2006, 84)
Lombroso’s views were shared also by Raffaele Garofalo and Enrico Ferri, who stated that any criminal behavior cannot be explained without involving another factors, such as environmental or physic.(Ferri 1901) It is worth considering, that Lombroso’s studies were widely criticized, because of showing significant overemphasize of biological causes, while an environmental factors seemed to be neglected by him. As it was stated in Wolfgang cited in Reid (2007; 88) “The fears of these critics that Lombroso diverted attention from social to individual phenomena, reveal their basic misunderstanding of his work and its effects (â€¦). Lombroso served to direct emphasis from the crime to the criminal, not from social to individual factors”
Although Lombroso and other positivists had made the foundations for further scientific analysis of criminal behavior, but the effective crime prevention requires changes in the environment and the social structures, which are also important in an explanation of the causes of crime.(Williams,2008; 162)
The physical approach of crime and human behavior, shows the assumption that “function is determined by structure”. The belief, saying that the crime is associated with body build, was introduced in the 1926 by Ernest Kretschmer,(Lilly 2007; 24-28) but the first real development of this issue begun with the scientific work of B. Sheldon in 1940. Sheldon connected psyche and body type with temperament. During his research, Sheldon introduced three body types: ectomorph- tall, skinny boned; endomorph- short, fat bodied; and mesomorph- athletic, well built. Main purposes of his research can be defined as a need of systematic study of human behavior and personality. Sheldon was further criticized about the way his sample was chosen. As it is stated in Cortez and Gatti, Sheldon picked only those persons, who could support his theory. His definition of three body types, has also been criticized because it was not precise enough to easily distinguish them. (Cortez, 1972;8).
The next step in an explanation of criminal behavior is to take closer look at the history of the family just to find out, if whether the family has had a cases of criminal behavior. The early studies of family were conducted by Sheldon Glueck and Eleanor Glueck. Researchers concentrated on family history to find the possible explanation of criminal activity. But it is worth to remind, that the family studies have been discredited because it was not methodologically sophisticated enough to permit significant conclusion. Although there was a basic difficulty in family studies, which consisted of the impossibility to control the environment, the family was existing and developing, it was necessary to take further steps in an explanation of a correlation between family background and criminal behavior of ones. This inconvenience led researchers to introduce two other methods of studying genetic factors and criminality. Those studies included the environment , as the most important factor affecting people’s behavior and leading to crime. Finally, aim of those studies were to find an explanation about the generations of violence and deviance within the families. Those two methods were studies of adoption and studies of twins.(Williams,2008; 139)
Studies of twins were conducted by Karl O. Christiansen, who studied the occurrence of criminal behavior among twins in Denmark, between year of 1881 and 1910. Christiansen stated that if one of twins is engaged in criminal activity, the probability that the second twin will also do so was 35%, and only 12% if the twins were fraternal. His studies were continued and updated by Sarnoff A. Mednick and his colleagues, who concluded that genetic factors for some variables are linked with criminal behavior. Mednick’s studies were criticized because of possibility of methodological errors, but finally were confirmed, despite of those errors occurrence there is an evidence of correlation between genetic factors and criminal behavior. (Burke 2009, 69-70)
Another important issue in Mednick’s research were studies of adoption. With his colleagues, Mednick conducted adoption studies in Denmark, using a sample of 72000 from Denmark’s adoption registry. Mednick stated that the tendency to criminal activity was higher among those adoptees, whose biological parents were criminals. Moreover, research showed that there were much higher tendencies of criminal behavior in adoptees, who had both biological and adoptive parents engaged in criminal activity. His research undoubtedly proved that genetic factors cannot be ignored when explaining causes of criminal behavior. (Mednick et al, 1987; 67-80)
Family studies were also a tool used to get the information about possible psychological explanations of crime. Early psychologists were focused mainly on intelligence traits. Research traced criminality in the same family through generations, showed that the mental retardation was the main cause of criminal behavior. It is worth to consider that one of the earliest explanation of the criminality in the middle ages, was demonology. People believed in evil spirits, which while possessing individuals, caused nasty behavior. Only exorcism seemed to be the right treatment, which could save possessed person from doing wrong things. In fifteenth century some beliefs arose that people, who were behaving badly, were actively cooperating with devil. In the enlightenment great discoveries about human body and mind were made, researchers started to be interested in human anatomy, physiology, neurology, medicine and chemistry. Causes of physical illnesses were discovered, and therefore researchers applied that there must be reasons, which causes mental disorders. Those assumptions led to development of psychiatry, defined as the prevention, diagnosis and treatment in mental illnesses. According to psychiatry approach, each person is individual and requires specific treatment and an individual case study. William Healy was the first, who used the case study to explain delinquent behavior., and the case study seemed to be the only way to penetrate the ones background, concentrating mainly on emotional development. Healy and his associates showed that delinquents were more likely to have personality disorders than non-delinquents. Although Healy et al introduced and popularized the case-study method, their studies may be criticized because of using too small samples as well as giving too little information on the way of measuring the concepts and characteristics. . (Reid 2006; 102-103)
Sigmund Freud (1856-1939) is widely known as the father of psychoanalytic theory. Freud introduced the concept of unconscious, and according to that, humans live with mental conflicts between desires and energies, the most basic instincts, which must be hidden because of society’s morality. The natural drivers can often be expressed by some persons in some ways, usually indirect, to avoid reaction of others. Freud saw twofold nature of every human being- assertive and aggressive. Aggression could not be learnt, but rooted deeply inside the mind. That was the reason why Freud stated, that everyone have the criminal tendencies, but during the socialization process, people learnt how to control it effectively.(Myers, 1995; 462-465) According to Halarambos(1991), the psychiatric approach may be criticized for some reasons- the terms were vague, no definitions for most concepts were given and the most of data were subjectively interpreted by the researchers, as well as the research were based on small samples.(Halarambos, 1991; 584-585).
In 1985 year publication “Crime and Human Nature” authors James Q Wilson and Richard J. Herrnstein stated that there is a link between criminal activity and a level of intelligence, especially low. However authors were criticized because of stating that low level of intelligence and crime appear together in the same group, but there were no significant evidence that low level of intelligence causes criminal behavior.(Wilson 1985, 148-164). According to Benson not only people with low level of intelligence commit crime, but there are also very bright criminals, especially white-collar criminals , so when taking intelligence level to consideration, it is important to consider also type of the crime committed. However, those with lower intelligence level are more likely to be arrested, charged and convicted.(Benson 2009, 19-50)