Biological basis of psychopathic disorder
Because the psychopaths impulsiveness, acting out and intolerance of discipline tend to appear early in life, several investigators have focused on the role of constitutional deficiencies as causative factors in antisocial personality disturbances.
- Malfunctioning of Inhibitory Mechanism in the Central Nervous System –
In a review and interpretation of studies indicating a relatively high incidence of EEG abnormalities among psychopaths, particularly those involving slow wave activity in the temporal lobe of the brain. Here (1970) concluded that such abnormalities reflect malfunctioning makes it to learn to inhibit behavior that is liking to lead is punishment.
It may be emphasized that most psychopaths don’t show abnormal EEGs and when they do, there is no conclusive evidence that the EEG patterns are directly related to the development of psychopathic personalities. In addition many individuals who show similar EEG pattern are not psychopathic. So when brain abnormalities do occur in psychopathic personality they are probably interactive factors rather than primary determinants of the maladaptive behavior.
- Deficient Emotional Arousal –
A good deal of research evidence indicates that psychopaths are deficient in emotional arousal; this presumably renders them less prone to fear and anxiety in stressful situations and less prone to normal conscience development and socialization.
In an early study e.g. Lybben (1957) concluded that psychopaths have fewer inhibitions about committing antisocial acts because they suffer little anxiety.
Eysenck (1960) concluded that psychopaths are less sensitive to noxious stimuli and have a slower rate of conditioning than normal individuals. As a result psychopaths presumably fail to acquire many of the conditioned reactions essential to normal avoidance behavior conscience development and socialization.
- Stimulation Seeking –
In a study comparing psychopaths and normal Fenz (1971) found that psychopaths seem to have insatiable need for stimulation.
Such findings supported the earlier view of Canay (1965) who concluded that psychopathic behavior is extreme form of stimulation seeking behavior.
- Tie-reditary Factors
Wilkin and his colleagues studied all men born in Copenhagen between 1944 & 1947 which numbered 31346. Out of this the investigators chase all those who were above 6 ft. tall (as it is considered that very tall men have a chance of XYY chromosome). The number of men they selected by this process was 4591. Necessary tests using blood and mucous smear obtained from check of each person were conducted to identify extra Y chromosome. They also obtained records of criminal offences, school reports and estimates regarding the intelligence of each of these persons. Finally they identified 12 XYY men out of which 5 had been convicted for one or more criminal offences, from the rest of the XY men, 9.3% as against 41.7% of XYY men, were found to have criminal records. It should not however be concluded from this that there is a relationship between extra Y chromosome and sociopathy.