Our energy and time are limited. Our personality determines which aspects of our environment are presented to us as more visible or "priority" when it comes to defining where to invest our energy. For example, some of us may choose to prioritize our own well-being; others, the attraction and retention of sexual partners, and still others, the protection and care of our children .
The different personality traits will also determine which strategies we will use to solve these challenges, and which of them we will tend to solve more successfully.
And on what basis do we select our strategies? It is generally an unconscious decision, forged from our early childhood, as we go along responding spontaneously according to our "innate tendencies". Little by little we learn the impact that these responses have on our environment. Over time, we will be able to actively select the environments where we feel that our "pool" of capabilities has the greatest likelihood of adaptive success.
All personality traits carry adaptive advantages and disadvantages. A high sensitivity to stress, for example, will allow a greater capacity for alertness, and better detection of potential dangers, both physical and social, while involving an unpleasant subjective experience, and a potential damage to the health of its bearer.