Another piece of evidence from Eysenck’s own 1990 study that showed a “higher concordance between identical twins than between same-gender fraternal twins reared together” which suggests that heredity plays a dominant role in determining personality differences (Feist, Feist ; Roberts, 2013, p. 411). Personality develops from birth on. There are certain aspects of human behavior that come from human nature. Humans have natural instincts to find nutritional sustenance, seek out love and affection, and ask for help with the things they cannot do for themselves.
From birth until the beginning of school age, which varies from child to child but is usually around age four or five, caretakers may notice certain behavioral traits which may mimic a personality type but essentially no permanent type has yet been established. Starting around age five until around age eleven people begin to develop the dominant personality traits begin to form and it becomes apparent as to how the child learns, such as if they are auditory or visual learners and if they work well in groups on solitary. From around age twelve or thirteen, when they are entering adolescence, traits that support the dominant feature begin to appear: how they make decisions, what they value in life, and their perception of things.
Starting around age twenty, adults start to learn how their personality traits fit in with the rest of the world. This becomes very apparent when peers become coworkers rather than fellow students. For some people, sometime between the ages of 35 and 50, people may hit what is called a “mid-life crisis” because they begin to see facets of their life that they did not develop and feel a strong desire to satisfy these. After around age 50, the personality is more disciplined that those of younger stages and this is usually due to life experiences.
The Unconscious. Carl Jung stated “There are certain events of which we have not consciously taken note; they have remained, so to speak, below the threshold of conscious. They have happened, but they have been absorbed subliminally” (Mlodinow, 2012, p.5). Influences that we are not consciously cognizant of influence our actions. Dream content has been shown to be a reflection of people’s view on religion. Disagreeing with the normal thought that Christianity and science “inevitably conflict with each other, dreaming offers an area of potential religion–science convergence” (Bulkeley, 2009).
View of Self. “Different aspects of the self emerge in different periods of the lifespan” (Klimstra, 2012). However, once new aspects of the self emerge, existing aspects do not finish growing. Therefore, it is important to consider several aspects of the self. Neuroscientists have performed studies using human brain mapping and have concluded that “People who endorse individualistic cultural values showed greater MPFC medial prefrontal cortex activation to general self-descriptions, whereas people who endorse collectivistic cultural values showed greater MPFC activation to contextual self-descriptions” (Chiao, Harada, Komeda, Li, Mano, Saito, Parrish, Sadato, & Iidaka 2009).
Personality types. The personality can be assessed using the Myers-Brigs Personality Type Indicator (based on the theories of Carl Jung). According to this instrument, there sixteen personality types made up of four criteria. (E)xtraversion versus (I)ntraverson give a clue of if the person is focused on the outside world or only their inner circles. How they process information by either by way of the five senses (S)ensing or if they look for patterns ntuition. People make decisions by either (T)hinking or by (F)eeling. Finally, the test also measures how people prefer to live in the outside world, structured which is called (J)udging or more flexible, (P)erceiving. An example of personality type would be INFJ who is described as
Seek meaning and connection in ideas, relationships, and material possessions. Want to understand what motivates people and are insightful about others. Conscientious and committed to their firm values. Develop a clear vision about how best to serve the common good. Organized and decisive in implementing their vision (Briggs-Myers, 2013).