Due to the nature of juvenile delinquency, the problem of personality is put first in the study of this phenomenon. A juvenile delinquent does not become one so suddenly, at the time of the commission of a crime. As a rule, antisocial properties of his personality are formed gradually and long before the commission of a crime, which gives rise to a new qualitative socio-legal assessment of his personality as a juvenile offender. In other words, in the commission of every crime, there is first a motivation, then the crime is planned and executed. Therefore, the main systemic elements of crime are the properties of the individual and the external environment, that is, social conditions of life. The causes of crime are analyzed by representatives of many sciences: lawyers, sociologists, psychologists, economists and even biologists. However, they do not provide an exhaustive explanation of all crimes. Consider then the discussion of biological and psychological theories about juvenile delinquents. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”? Get the original essay Biological theory. Early attempts to explain crimes were mostly biological in nature: scientists looked for naturally conditioned reasons to explain the propensity of certain people to commit crimes. Italian criminalist Cesare Lombroso concluded in the 1870s that some people are born with criminal inclinations. According to him, types of criminals can be defined by the shape of the skull. Lombroso does not deny the influence of society on the development of criminal behavior, but believes that most criminals are biologically degenerate. Subsequently, ideas about biological predisposition to crime have been heavily criticized. In the second half of the 20th century. Attempts have been made to link criminal inclinations to a certain set of chromosomes in the genetic code. It has been suggested that among criminals committing serious crimes, the proportion of people with an extra Y chromosome is disproportionately high. In a number of studies carried out in high security prisons, the result was found to be one person in hundreds of prisoners, compared to one person in a thousand in the ordinary population. However, the researchers quickly had the intuition that this result was due to the small sample size. Studies of larger populations have shown that men with an unconventional set of chromosomes are no more likely to commit violent acts than those with a normal set. Psychological theory. Psychological theories of crime, like biological ones, link criminal inclinations to a certain personality type. In the 20th century, some psychologists, drawing on the ideas of Sigmund Freud, suggested that a small number of people developed an “immoral,” or psychopathic, personality. According to Freud, most of our moral qualities come from restraint, which we learn from early childhood. Due to the special nature of the relationship with parents, some children do not develop such restrictions and, therefore, do not have a basic moral sense. Psychopaths can be described as autonomous people who enjoy violence for its own sake. Psychological theories of crime have, unlike biological theories, a rational grain. However, at best, they can only explain certain aspects of crimes. Although an insignificant minority of criminals exhibit characteristics..