Biological theories of personality explain personality based on neurochemical brain activity and based on genetics. The most well known is Eysenck's Three-Factor Model of Personality. A newer one is The Five Factor Model.
Eysenck's Three Factor Model explains personality based the degree of three personality factors an individual personality expresses:
- Psychoticism (added after the original two)
The Five Factor Model measures degrees possessed of five personality factors:
The subject of Kennedy's personality is a vast one about which books have been written and movies made. Let's look at three manifestations of one trait and see which of these two biological theories of personalty help best to explain him.
1. It is known that Kennedy got special permission to join the Navy in World War II because having a degenerative spinal disease and being a sufferer of Addison's Disease, he would never have passed a military medical exam. It is speculated that JFK was convinced that a career in politics would have been impossible without having served in WWII, so he used his family's prestige, clout and money to attain an officer's post in the Navy.
2. While the commander of a PT U-boat, the U-boat was overtaken and run down by a Japanese destroyer. To save the life of one crew member, he took the man's belt in his teeth and swam six miles to take him to safety, then going back to save the rest of his crew. His U-Boat was lost, but he saved all his crew.
3. When Kennedy was facing the Bay of Pigs Cuban missile crisis, his military and Cabinet advisers urged him to evacuate with them and Vice President Johnson to a safe underground shelter since the missiles were aimed at Washington D.C. Kennedy is reported to have said that as long as Americans were at risk, he and they would stay right where they were, the prime target, so the advisers had better come up with a much better plan of action.
These three incidents show the same personality trait: when in demanding circumstances, Kennedy threw personal caution aside and acted decisively. In the first, he threw law and common sense aside to secure his future aspirations though to do so meant employing corrupt, illegal means. In the second, he acted out of the highest standard of selflessness and loyalty knowing that doing so put his life in peril both from the ocean elements, including exhaustion, and from his medical condition which could be adversely triggered by physical trauma. In the third, he acted out of the highest nobility a leader can show by permitting himself to remain a target for the goal of finding a means of preventing his people from being targets.
By Eysenck's model, these three incidents show Kennedy to have been a Stable Extrovert with low levels of Passivity and considerable levels of Aggression. By the Five Factor model, Kennedy is shown to have been an Open and highly Conscientious, highly Stable Extrovert with low levels of Agreeableness, (he controlled rather than submitted to being controlled). The models agree while using different biological markers for measuring confirming results.
Five Factor Model