Evolutionary Psychology and Personality

By: Dr. Susan Siegfried, Clinical Psychology

The Difficulty in Combining Personality Theory and Evolutionary Theory

Personality is a combination of thoughts, motives, distinctive behaviors, enduring behaviors, and emotions. This combination of knowledge about a person predicts how we will react and adapt to given situations. When we talk about personality we need to talk about theory as personality is unique to each individual and it changes over a life time. The trait theory suggests that personalities are a genetic accumulation of general traits that remain over a life time.  These traits include:

  1. Introversion/Extroversion: Extroversion is focusing your attention outward first rather than inward toward your self which would be introversion. So this is the difference between that quiet shy person and the outgoing people person.
  2. Contrary/ Agreeable: Contrary refers to the individual who is very cautious and not likely to be concerned about the needs of others before themselves. Some suggest this in an individual who is anxious or scared. The Agreeable individual tends to trust, be altruistic, affectionate and kind.
  3. Unreliable/Conscientiousness: An unreliable person is just that, not to be depended upon. They do not go the extra mile for others even in a committed relationship. The Conscious person is thoughtful, have good impulse control and show goal-directed behaviors.
  4. Neuroticism/ Emotional Stability: This is not as bad as it sounds. Neuroticism just means that individual that tends to be more pensive or moody.  They tend to have more ups and downs in their feelings. Emotional stability is the individual who is more even tempered.  This is a differences that is about control of what one shows to the world not a differenced in how much an individual feels.
  5. Seclusion/Openness: The secluded individual likes thing just the way they are.  They do not have an interest is trying or learning new things or new ways of doing or thinking about what they already know. The open person is imaginative, has good insight into process and people and tends to be interested in many things.

There are other theories of psychology; however, they tend to be more existential. Freud you will remember came up with the Id, Ego and Superego. When we are working with evolutionary psychology we must remember it is more biology based.  It is easier to quantify dependability a trait than it is to quantify the id. Evolutionary psychology has been able to identify species –typical and sexual adaptations when applying it to psychology one must look at evolution on a smaller scale. The real question is, how can evolutionary psychology explain personality with its many individual differences? The trait theory tells us that personalities are different having a continuum upon which all people fit. While the traits may be the same in everyone where we are in that trait is our alone to own. As hopeless as it may see to pin this all down in scientific terms it is interesting to note that evolutionary psychology has made many major strides which are proving to be helpful to further the science and also are useful to the field of therapy.

What are Researchers Working on in Terms of Personality  (Buss, D., 2009)

We only have a short time in life to accomplish what we choose to accomplish. Our energy (time) is finite. We must make trade off in how we use it. What we have begun to learn from this research is what drives one person in one direction and another person in another direction. So far, it seems to be basic biology. For example, higher testosterone levels in a male seem to cause that individual to spend more time on mating and less time on parenting. This would be considered predictive information for a therapist.

Costly signals tend to be positive signals that we send to attract others whether it is for mating or business.  People tend to be attracted to the more costly signals.  For example, giving away money, throwing a lavish party or buying expensive gifts tends to attract more people to you.  This may explain some of the disparity between economic classes.

We find environmental heterogeneity in fitness optima maybe necessary for survival.  For example, we know that people who have lived on small islands near Italy for twenty generation show much lower scores on openness and extroversion.  This adjustment allows people to adapt to particular situations. This allows then for prediction of success based on the Trait assessment.

Frequency-Dependent selection is also an interesting discovery from evolutionary psychology.  When several strategies for success or survival are maintained within a population the usefulness or fitness of a strategy decreases as it becomes more common. Example: as the ratio of men to women increases in a population the average fitness of the male decreases. This theory has been used to explain psychopathology. When things are out of balance the individual must find new and unique methods of getting their needs met.

These tend to be the main theories about personality that evolutionary psychology has proposed at this point in time.  There are more possible theories they are looking at but they need more research.  This is a very open area for this type of research.  The Frequency-Dependent theory has been looked at the most recently in the wake of the increase in mass violence in many successful societies today.  Some would propose that we need to look at our social balance to observe relationships to the individual changes in how we are competing today. Is the individual become so insignificant that one must do something big to get their needs met?  How could we address those needs as a society in a positive way? Why does the individual need to choose violence to meet those needs?  Are we creating a dichotomy between those that can achieve and those that can not?  Truthfully we are getting into a bit of sociology at this point but it is interesting none the less.

What have we learned for psychology today from the evolutionary researchers? Therapist and cognitive researchers are looking more and more in to personality theory to form treatment plans that allow individuals who are struggling with the fit of their genetic personality traits with success within their environments.  How do we teach the contrary individual to be affectionate and kind so as to facilitate long term relationships both personally and professionally?  Understanding how this all works shows the importance of thinking in these terms which is somewhat new to therapeutic psychology.


Buss, D. M., (2009). Explaining personality and individual differences. Association for Psychological Science, Vol. 4, No. 4, 359-366.