The psychology of personality is concerned with describing fundamental ways in which people differ. The scientific study of personality looks for the patterns in individual differences, classifies these patterns, and seeks to give explanations for them. There are two main groups of personality theories. One group concentrates wholly on differences within the "normal" population. The other group is concerned with those differences that lead to "abnormal" behavior, to poor psychological health, and to mental illness. This second group is concerned with psychopathology. Both groups of personality theories are relevant to understanding religious and spiritual development in childhood and adolescence. The first group of theories helps to address the question whether there is a link between personality and religion or spirituality. Are some personality profiles more conducive to religious and spiritual development than other personality profiles? The second group of theories helps to address the question whether there is a link between psychopathology and religious or spiritual development. Is religion and spirituality associated with better or with poorer mental health?
Before examining these questions further, it is crucial to distinguish between two similar but very different terms, namely, personality and character. Character is concerned with how people develop and grow (good or bad). Character can change and be changed. Personality is concerned with the much deeper concept of how people are made. Most personality theorists try to delve below the surface. According to this, personality is as much of our basic makeup as being male or female, having brown eyes or blue eyes, being born with blond hair or black hair. Many religious traditions are concerned with reshaping peoples' character, but they need at the same time to accept and to work with peoples' personality. Expecting people to change their basic personality in response to religious conversation may be as mistaken as to expect them to change the color of their eyes or to change their sex.
From a theoretical point of view, over the years the psychology of religion has advanced very different theoretical perspectives regarding the relationship between Christianity and psychological health. One position has taken the negative view that religion is associated with lower levels of psychological health, while the other position has taken the positive view that religion is associated with higher levels of psychological health. The negative view is exemplified in the classic writings of Sigmund Freud, who sees the Judeo-Christian tradition as capturing the human psyche in a state of infantile immaturity, leading to psychological vulnerability and neuroses. The opposite psychological view is exemplified in the classic writings of Gordon Allport, who sees the religious images of the Judaic-Christian tradition as providing powerful developmental tools promoting and leading to psychological health.
A particularly interesting and powerful model of personality used in studies of religion and spirituality is the three-dimensional model developed by Hans Eysenck. Eysenck's three-dimensional model of personality has been employed in a large number of studies since the late 1970s to attempt to adjudicate between these two conflicting theoretical positions on the relationship between religion and mental health. The strength of Eysenck's model of personality resides in the way in which he unites perspectives from abnormal psychology and normal psychology. Eysenck argues that psychological disorder or abnormality is not categorically discrete from normal personality. For Eysenck, psychological disorder is located at one extreme end of normal personality and remains continuous with normal personality. The Eysenck Personality Questionnaire distinguishes between two psychopathologies, neurotic disorders and psychotic disorders.
In Eysenck's model, neurotic disorders lie at one extreme of a dimension of normal personality, ranging from emotional stability, through emotional lability, to neurotic disorders at the extreme end. Eysenck characterizes people who score high on the neuroticism scale but who fall short of neurotic disorder in the following way. They are anxious, worrying individuals, who are moody and frequently depressed. They are likely to sleep badly and to suffer from various psychosomatic disorders. They tend to be preoccupied with things that might go wrong and with a strong emotional reaction of anxiety to these thoughts. In Eysenck's model, psychotic disorders lie at one extreme of another dimension of normal personality, ranging from tender-mindedness, through toughmindedness, to psychotic disorders at the extreme end. Eysenck characterizes people who score high on the psychoticism scale but who fall short of psychotic disorder in the following way. They are described as cold, impersonal, hostile, lacking in sympathy, unfriendly, untruthful, odd, unemotional, unhelpful, lacking in insight, strange, and with paranoid ideas that people are against them.
According to Eysenck's theory, neuroticism and psychoticism are totally unrelated to each other. To know where individuals score on one of these dimensions of personality does not help you to predict where they score on the other dimensions. In other words, these two dimensions are orthogonal to each other. Eysenck's dimensional model of personality adds a third orthogonal dimension to these two dimensions of neuroticism and psychoticism. The third dimension, which is not itself concerned with psychopathology, ranges from introversion, through ambiversion, to extraversion. Extraverts are characterized as sociable introverts who like parties, have many friends, need to have people with them to talk, and prefer meeting people to reading or studying alone.
Within a Christian context, studies using Eysenck's model have been reported in Australia, Canada, France, Germany, Hong Kong, the Netherlands, Norway, and South Africa, as well as in the United States of America and the United Kingdom. Studies have also been reported in a Jewish context in Israel. The evidence from these studies is consistent and conclusive. Using Eysenck's scales, there is no evidence to support either a positive or a negative relationship between religion and neuroticism. Using Eysenck's scales, there is wide evidence to support a negative relationship between religion and psychoticism. In other words, religion is associated with lower psychoticism scores. Using Eysenck's scales, there is no relationship between religion and either extraversion or introversion.
Looked at from another perspective, there is, on the basis of these studies, a recognized link between personality and religion. Although the two personality dimensions of extraversion and neuroticism are independent of religion and spirituality, the third personality dimension of psychoticism is related to religion and spirituality. Those who record lower scores on this dimension of personality (those who are tenderminded rather than tough-minded) are more likely to be drawn to religion and to spirituality.
There are two main conclusions that can be drawn from this research tradition regarding the relationship between religious and spiritual development and positive development. The first conclusion is that a clear link exists between at least one major personality dimension and religion. The second conclusion is that there is no empirical evidence to link psychopathology and religion within general population studies.