Hans Eysenck's description of personality has been an influential model in personality research for several decades. Hans believed that biological factors played a huge role in our personalities, hence the term biological psychology.
Biological psychology is the branch of psychology, which includes studies of the various biological bases of behavior. These include the study of neuroanatomy and physiology, the influences of hormones and other chemicals, and the genetics and heritability of behavioral traits. Biological psychology is one of a group of brain sciences called the neurosciences. Neuroscientists as a group are interested in all the diverse aspects of the nervous system, while biological psychologists in particular are more specifically interested in the biology of behavior.
Eysenck was opposed to the psychoanalytic theories of Freud, claiming that that he was not empirical enough. Early research involved a factor analysis of a psychiatric population where two major factors were determined .
Factor 1: Degree of neuroticism. .
Factor 2: Type of neuroticism. .
This was the basis of his original model of personality, which consisted of two very clearly marked dimensions of human patterns of behavior. .
Neuroticism emotional stability versus emotional instability. .
Extroversion versus introversion. .
Eysenck claimed that introverts having a more highly aroused cortex were more sensitive to excessive stimulation and sought to avoid it and that extroverts having a more under aroused cortex actively sought additional stimulation. This, Eysenck claims, is supported by drug studies using stimulants and depressants and studies with involuntary rest periods. .
Eysenck claims that neurotics have a higher level of brain activation than do stable or normal individuals. Eysenck claimed support for this with tasks that involved increasing difficulty and frustration. .
Development of personality.
Eysenck believed that there were two types of neurotics.