Preferred fight or flight response indicates a difference in personaliy

There are two recurring patterns to respond to dangers or threats seen in nature: to fight or to flee. Although both options will be present, a first preference seems to be genetically determined. It would makes sense. In nature, whether or not to be able to respond quickly to a threat is often a matter of life or death. Then you do not need to think twice on the reaction. This preference leads to profound differences in muscular, cognitive and behavioral development. You can speak of a difference of character. In-group-living animals sometimes within the same species have sometimes these differences in character development, a functional specialization for the group survival. The 'fighter' is the one  who is looking for new ways to get food, takes risks. An example that the 'fittest' does not always have to be the best survivor, he is geared up for the survival of the group as a whole to take risks.

The two character types have been studied in rats-in-groups. When rats are fighting, they do that with the mouth. One type, the "risk taker", rankles much permanently and the other not much. This shows how far-reaching these differences are. In humans, the difference in tendency to fight or to flee are to be found in the archetypes of the extraverted towards the introverted character, the one type reacts in "danger" (as the stress hormones adrenaline and cortisone are activated) initially with anger (the fighter type) and the other type with a primary reaction of scareness (the fleeing type). These basic characteristics also influence the development of the interest of a person. The introverted type will more likely focus on music, rather than on fighting.
Moreover, women generally have a very different response to 'danger' than men have (even if they have similar genes). When they have stress they will look for social contacts even more often than they tend to do as usual. 

Three character components
vechten_ptVluchten_ptmoeder_met_kind_ptIn animals within the two character types fight or flee one can observe gradual genetic-determined differences in the degree of fight and flight. In humans also are both behavioral responses to varying degrees present. A third component in the character is the (degree of) activation of the opioid (love-) areas in the brain. Based on combinations of these three components and their differences of degree, the psychologist Cloninger identified 24 personality types. As fight and flight in humans are associated with strong emotions like anger, fear, triumph and pride, the opioid areas are associated with strong emotions from joy and sorrow. The character is so connected with the most emotional. Emotions tend to occur in relation to other people.

Character development 
The conclusion is that there are many different characters connected to different 'institutions' of those 3 basic systems (Spinoza suggests that there is another system, a system which connects with other people. This system is to Spinoza 'the highest good', which gives a durable good feeling, a 'reward' of internal 'Peace'). Most probably distribution in characters is a good survival strategy for humans. It provides flexibility in adapting to the environment. Extra flexibility is that some genes may change even during development, because these genes can be influenced by the environment. This is called epigenesis. Epigenesis is most clearly demonstrated in the influence of hunger, it seems (to me) likely that other hormones too are associated with epigenetically functioning systems.