Criminology recognizes three groups of theories, which attempted to explain crime causation. Crime was explained by biological, sociological and psychological theories. Three different types of criminological theories attempted to answer what is causing of crimes. Each criminological theory tried to establish its high level of credibility and reliability. Classical theory was first established as a part of modern criminology, but turning points for development of scientific method in criminology began in 19th century soon as criminology pioneers implemented them in the etiological research of crime. Furthermore, at that point it became possible to study criminology in the scientific manner, although concepts that involved crime causation and foundation of modern criminology began with a critical and rational approach of classical criminology. Identifying the cause of crime from the theory standpoint became a specific and major task of criminology.Classical criminologists believed that criminal behavior is best represented by a free will and their theory views on criminality were purely philosophical. Positivists sometimes called Italian school of criminology, because its major representatives were Italian national, emphasized the collection and analysis of data on the biological and social causes of criminal behavior.Ferry proposed a classification of criminal types, which included the born or instinctive criminal, the insane criminal, the passionate criminal, the involuntary criminal, the occasional criminal, and the habitual criminal. The occasional and habitual aren’t innate criminals, but the products of unfortunate family or societal circumstances. According to Ferry, the true criminal is one who lacks basic altruistic sentiment of honesty and pity.  Ferry used both sociological and biological factors to explain a cause of crime. Rafael Garofalo contribution to criminology was that he found that certain forms of criminal behavior might be encouraged by social and environmental circumstances, and this set a path for numerous experiments and scientific expertise on the way to define crime causation.

Psychological theories of crime came to the existence around 1913, and their primary concern was to find a supporting link between crime and  low intelligence. Furthermore, psychological researches found  the difference of 8 points in IQ scores between delinquents and non-delinquents. Besides IQ testing in criminal psychology, other researchers dealt with personality disorders i.e. Robert Hare made an extensive research of psychopaths, sociopaths and antisocial personalities. Hare identified the mechanism and made a classification of psychopaths.

Social theories of crime

The evolution of sociological theories of crime began in 19th century and continued today.Social theories of crime researched cultural and social factors that lead to criminal behavior. Structural theoretical approach stated that certain groups within a society have less opportunities to achieve the goals most valued by a society. Society demands that people should reach social respectable goals, but acceptable methods are hard are hard to comply and goals are often unreachable in the such way.  Because the opportunities are not the same for all, the society is contributing to crime. Other social theories like subcultural theories of crime have researched the discrepancy between social norms and systems of value and the norms and values of a specific subcultural group. Research of juvenile delinquency and youth gangs found that criminal behavior directed towards living up to values of delinquent subcultural group.Conflict theory states that society is based on conflict between competing social classes. Conflict theory came to the existence in 1960’s and is based on the perpetual conflict between powerless and powerful. Ecological criminology was developed in 1920’s at the University of Chicago.  Theorists of ecological criminology were called Chicago school of criminology. They claimed that crime is a result of disorganized eco-areas, but have disregarded personal traits of people who live in those eco-areas. Multi factor criminology theories of criminality are integration of societal, psychological and biological/biosocial theoretical approaches to defining crime causation. Criminology multiple factor theory began its development as an interdisciplinary study to integrate valid elements of theories in a single "corpus" of crime explanations.

Biological theories of crime  made the common assumptions that physical traits can lead an individual to criminal activities. Generally speaking, it was thought that physical attributes were passed down from parent to child. It was thought that the risk of committing of crimes also passed down from parents. The early biological theories of crime were focused mainly on heredity of crime, and made rather quick assumptions about the research findings.

Biological theories of crime causation