This essay will attempt to give an explanation of crime in terms of theories of individual behaviour by describing the physiological, biological and psychological explanations of crime; this essay will also describe theories of abnormal behaviour and crime.

Research into criminal behaviour attempts to explain what physiological, biological, genetic and psychological factors influence one person to indulge in acts of delinquency, to break the law, to be criminal, while other people live out their lives without overstepping these social and moral boundaries. We need to recognise that most people break the law at sometime in their lives e.g. driving offences such as speeding, dropping litter, under age drinking, experimenting with illegal substances, working within the black market economy and purchasing black market products and counterfeit goods. Criminological theories attempt to explain why some individuals persist in criminal behaviour over and above the norm.

Cesare Lombroso was responsible for popularising the notion that people were born criminal i.e. they were biologically predetermined to be criminals. He published his work l’Uomo Delinquente in five editions from 1876 to 1897. His idea’s are unsurprising when one considers that Darwin’s theories were very influential at this period in time, Lombroso subscribed to the notion that criminals were primitive throwbacks from an earlier time in man’s evolutionary development and therefore were both mentally and physically inferior. Lombroso gave the world a physiognomic checklist of features, defects or deformities with which a criminal could be identified. The list is quite extensive and covers most physiological characteristics, which are variations of the average, build of a human male and include aspects of phrenology. Furthermore he indicated that the criminal had other non physical characteristics which included sensory abnormalities such as acute sensitivity regarding pain, touch and sight with less acute taste, smell and hearing; functional differences such as improved agility, ambidexterity and strength; a lack of morals; differences in language usage and idleness. He also made the claim that all criminals were epileptic. Lombroso believed that his work was based on scientific study methods as opposed to philosophical methods used by previous “criminologists”. Lombroso measured to skulls to gain information regarding the cranial capacity of the criminal, this work was criticised because it was undertaken without regard for age or physical build. Lombroso’s sampling methods were also criticised because his study group consisted of male Sicilian prisoners who all shared physical characteristics due to their ethnic make up, this sample group was not matched with a control group from the general population and the research can therefore be criticised as being biased. Sheldon (1949) modernised this theory of delinquency being apparent in physical appearance he related certain personality traits to body shapes, which he grouped into three basic body types, endomorphic, mesomorphic and ectomorphic. Sheldon tested his theory against a control group and concluded that mesomorphs were most likely to be delinquent. (source: http://faculty.ncwc.edu/toconnor/criminology.htm)
Franz Joseph Gall (1758-1828), was the first to make a link between the personality of the individual and the Morphology of the skull, a science we now call Phrenology. Gall considered the Brain to be the home of all mental activities (Http://134.184.33.110/phreno/intro.html). Gall based his works on the following principles;
· That moral and intellectual faculties are innate
· That their exercise or manifestation depends on organisation
· That the brain is the organ of all the propensities, sentiments and faculties
· That the brain is composed of many particular organs as there are propensities, sentiments and faculties which differ essentially from each other.
· That the form of the head or cranium represents the form of the brain, and thus reflects the relative development of the brain organs.
(Http://134.184.33.110/phreno/intro.html)

Although in the early years phrenology was viewed as a side show tool similar to fortune telling in the 20th century it attained credibility with evolutionists and Criminal anthropologists, but was attacked as being unscientific by the psychoanalytical school of psychology, possibly because it attributes personality to the physical and not the ‘ inner’ being.

Early Genetic research into predisposed delinquency points to an extra Y (male) chromosome as being significant, Jacobs, Brunton & Melville (1965) found that there were larger numbers of XYY males in mental institutions than in the population as a whole and that these men tended to be taller than the average male. Jacobs defined these men as having ‘dangerous, violent or criminal propensities’ (Williams, 4th edition, 2001, p147). This research was overturned by later studies which concluded that XYY men were actually less aggressive than their XY counterparts, Sarbin & Miller (1970) & Watkin et al (1977). These studies found that XYY men were over represented in mental institutions because of an increase in mental retardation, those XYY men who had participated in criminal activity were found to be involved in petty crimes rather than violent or serious crimes(Source: Williams, 4th edition, 2001, p146-147).

Further extensive genetic studies into crime have taken place. Twin studies carried out by Lange (1929), Christiansen (1968 & 1974) and Dalgaard & Kringlen (1976) showed that monozygotic twins have a greater concordance rate than dizygotic twins, however Rowe & Rodgers (1989) The Ohio Twin Study, concluded that although some of the concordance is due to genetic factors in MZ twins, the interaction between twins plays a greater part in shaping behaviour. Rowe decided that the studies were not conclusive in proving that genetics were responsible for criminal behaviour. Adoption studies were thought to be a more conclusive method of assessing genetic responsibility for criminal behaviour Hutchings and Mednick (1977) their extensive study found that there was only a 0.031 correlation between heredity and crime. Cadoret, Cain and Crowe (1983) concluded that both genetic and environmental factors combined influence whether an individual will participate in crime. Walter (1992) analysed previous twin and adoption studies and concluded that a combination of sociological, environmental and genetic factors were all contributory to delinquent behaviour. Ellis(1990a) studied natural selection in relation to genetic evolution and concluded that certain types of crime had a greater genetic basis than other types of crime these being rape, assault, child abuse and property offences (Williams, 4th edition, 2001,p155). Genetic research accepts that there are other factors involved which predispose an individual to delinquency, pointing to a combination of contributory factors both nature and nurture.
Another explanation offered for criminality is that of biochemical factors. Most women experience the extreme surge of hormones prior to or during menstruation. This surge of hormones can alter their behaviour for short periods and they may experience strong mood swings during this period from passive to aggressive behaviour, therefore perhaps a bio-medical explanation could provide the answer as to why some people will indulge in criminal behaviour while others do not.

Rose, Bernstein, Gorden and Catlin (1974) studied the effects of testosterone in monkeys and concluded that it was related to aggression and that environmental stimuli had an effect on testosterone levels within the individual monkey. Studies by Persky and Basu (1971), Smith and Scarmella & Brown (1978) on testosterone in human males found that in most men testosterone levels do not significantly affect levels of aggression (Source: Williams, 4th edition, 2001, p 168). Contradictory findings were made by Dan Olwens (1987), whose research found that there was a connection between male verbal and physical aggression and testosterone. A study by Ellis & Coontz (1990) found a correlation between testosterone peaks during puberty and early 20’s and the highest crime rates
Olwens found a similar connection between adrenalin, aggression and anti social behaviour. Mednick et al (1982) found that violent criminals needed stronger stimuli to arouse them because of lower levels of adrenalin. Therefore an individual with low adrenalin seeking excitement may indulge in violent acts to obtain the cortical arousal they seek, they will also take longer before the excitement from their actions subsides. A study by Fishbein (1990) found that there is often a biological imbalance in the hormones, neurotransmitters, toxins and metabolic products among individuals with psychopathic tendencies and ASPD..
The connection between substance abuse and criminal behaviour is well known and documented, however the act of buying and taking (self Medicating) certain substances is in itself an illegal act which instantly transforms the substance abuser from a law abiding citizen into a criminal. Drugs both legal and illegal are known to affect the neurotransmitters in the brain such as dopamine, serotonin and norepinephrine. Altering the level of these neurotransmitters can have an affect on aggressive behaviour, suicidal tendencies and mood, and can therefore possibly be linked to criminality in some people. Certain vitamin deficiencies can also affect the levels of neurotransmitters in the brain, a deficiency of the vitamin B can have an effect on serotonin levels because it helps the body to absorb vitamin C, which helps the body absorb sunlight , which in turn helps the body produce serotonin. However for a complete picture the psychological, environmental and sociological factors, which affect the individual have to be considered.
Nutrition has also been linked to criminality because nutritionally induced biochemical imbalances alter behavioural patterns. It has been suggested that there is a link between hypoglycemia and criminal behaviour because hypoglycemia results in mental confusion, violence, emotional instability and delirium. Clapham (1989) found that in extreme cases the hypoglycaemic individual may also be prone to automatic behaviour and retrograde amnesia, (source: Williams, 4th edition, 2001, p174). Virkunnen (1987) linked anti-social behaviour to hypoglycemia, this is unsurprising if we consider that alcohol lowers blood sugars and is linked very closely to violent behaviour patterns.
The psychoanalytical approach to crime is based on the notion that there is an internal conflict in the individual between the sub conscious and the unconscious mind, this conflict needs to be resolved in order for the individual to alter their criminal behavioural patterns. Central to this approach is the role of the super-ego. Aichorn (1963) discovered that an under developed super ego resulted in delinquent behaviour that prepared an individual for a life of crime, these individuals had as a result of bad parenting and other agents of socialisation not learned the social norms and values which are important in producing law abiding individuals. According to Aichorn a safe happy environment must be provided for the individual so that they can develop their super ego and avoid a predisposition for criminal behaviour. Aichorn recognises that not all criminals have an under developed super ego, (source: Williams, 4th edition, 2001, p195). This psychoanalytical approach shares common ground with Bowlby’s theory of maternal deprivation, this theory links maternal deprivation in early childhood with psychopathy. However the psychoanalytical approach is based on hypothetical constructs and ignores the involvement of rational thinking in some types of crime, there is also little empirical evidence to support this approach.
Psychology as a discipline has produced some strong evidence through longitudinal studies, which aid understanding of who will commit crimes. Psychology shows that in both males and females delinquency starts to increase from age 8 onwards to a peak at about 17 yrs of age when acts of delinquency begin to decline, Hollin (1999), (Gross, Fourth edition, 2001, p683). This increase in delinquency coincides with puberty and the delinquent acts are usually non-index offences such as under age drinking and truancy, although young people do commit both index and non-index crimes. Moffitt (1993) describes most crime as ‘adolescence limited’.
Farrington & West 1990; Farrington 1995 conducted a study into delinquency in 8-10 yr olds and followed them as they grew up, they concluded that the intensity and severity of both personal and social disadvantages were predictors of chronic offending in adolescence and adulthood. This longitudinal study is according to Hollin (1999) the most widely cited in the UK, it began in 1961 and is still in progress, (Gross, Fourth edition, 2001, p684).
Eysenck’s Personality theory illustrates that criminals are usually Neurotic Extroverts, those whose anxiety levels are driving them to seek ever-greater thrills with little conscience to limit their behaviour. They are individuals who have not received appropriate social conditioning and therefore have not developed the ‘appropriate’ responses in a social setting. Eysenck recognised that there was another factor, which had an even stronger correlation with criminal behaviour, Psychoticism. High scores in P coincided with aggressive , uncaring behaviour, an inability to empathise or feel guilt. Eysenck therefore reasoned that individuals who were Neurotic extroverts with high psychoticism were most likely to be criminal, he did however explain that this theory cannot be used to explain all crime. Claridge (1981) found a close association between P and overt Aggressiveness and Impulsivity, ( Gross, Fourth edition,(2001), P687). Farrington (1994) found a link between impulsiveness and offending but other studies such as Trassler (1987) and Little (1964) did not accept Eysenck’s theory.
Social Learning theory views criminality as learned behaviour through both classical and operant conditioning. This theory suggests that children fail to learn the correct responses to anti-social acts and may not have acquired appropriate conditioned fear responses. Although this theory can be applied to certain crimes more than others it is useful when considering cultural and gender differences in crime.
Anti-social Personality disorder and Psychopathy are all similar disorders but according to Proffessor Hare Most Psychopaths are anti social personalities but not all anti social personalities are psychopaths. Medical research has shown that in a psychopath there is damage to the amygdala or emotional centre of the brain, where dopamine is concentrated, this damage is also apparent in schizophrenics. This means that the emotional functioning capabilities of the psychopath are impaired and explains the cold, insensitive crimes often committed by such individuals, although one must remember that not all psychopaths resort to criminal behaviour. The criminal psychopath is not classified by the legal term of insanity because the crimes of the psychopath are often meticulously calculated, it is presumed that the criminal activity of the psychopath is a conscious choice unhindered by feelings of guilt or remorse. The 1983 Mental health Act defines psychopathy as follows; ‘Psychopathy means a persistent disorder or disability of mind (whether or not including significant impairment of intelligence) which results in abnormally aggressive or seriously irresponsible conduct on the part of the person concerned’ (Gross, 4th edition(2001), P688). The following list is not in-exhaustive but gives the basic personality of the psychopath; an inability to develop warm responsive, and affectionate relationships, a general lack of empathy, an unstable lifestyle, an inability to accept responsibility, particularly for their own unacceptable behaviour, they do not have psychiatric problems nor are they unintelligent, they have problems in controlling their behaviour, (Katherine S. Williams, 4th Edition,(2001),P253).
Ian Brady in his book ‘The Gates of Janus’, tells the reader that he has no feelings of guilt or remorse regarding his crimes, infact he appears to revel in the power he still exerts over the media and the families of his victims regarding the location of as yet undiscovered graves. Ian Brady is recognised by Psychologists as a higher order psychopath, however he views psychotics as being infinitely more dangerous and refers to himself as ‘a psychotic, a rose by any other name …. ‘, (Ian Brady, The Gates of Janus, 2001, p85).
A psychotic individual is accepted as insane by the legal definition, their crimes are often haphazard and unplanned. The individual in the throes of a psychotic episode is unpredictable and has no control or reasoning concerning his actions and will therefore not even make an attempt to hide the crime he has committed. A psychotic when lucid may exhibit signs of guilt and remorse concerning his actions. Psychosis affects the whole personality, contact with reality can is lost, the psychotic is unable to distinguish between external reality and subjective experiences, such as hallucinations and delusions, a psychotic lacks insight, the behaviour of the psychotic is discontinuous with ‘normal’ behaviour, there is usually no precipitating cause, psychotics disturbances are unrelated to the individuals premorbid personality.
Both Psychopaths and Psychotics are suffering from a mental illness it is the legal definition of insanity that differentiates between the treatment of criminals suffering from these disorders.

Various research appears to support and link the theoretical approaches of physiology, biology and psychology and they all concur that environmental and sociological stimuli play a part in what predisposes an individual to crime, only by looking closely at all the factors involved in the make up of a criminal can a true picture of what motivates and predisposes an individual to criminal activity be discovered.