Evolutionary Psychology and Emotions

By: Dr. Susan Siegfried, Clinical Psychology

Human Emotion

An emotion has four parts.  First you appraise the situation to determine if you are safe. Second, you experience a subjective feeling.  Third you have physiological responses.  You heart rate may increase or slow down, your breathing changes and hormones are likely released.  Finally, you show some observable behavior. This could be anything from smiling to crying to running.

Overview of theories explaining how emotions work

James-Lang theory of how emotions work is likely the most accepted basic theory.  He says that first our brains read physiological changes in the body such as increased heart rate.  Then your brain interprets different pattern in those changes. Then those patterns trigger different emotions and then you finally  outwardly react, ie. smile, scream or run. So, first you see the bear, then the brain checks things out with past brain patterns, then you know your are scared and finally you run (or what ever other behavior your basic psychological traits or past experience, or knowledge push you to do).

There is a facial feed back theory that says you brain reads you automatic facial expression and then reacts based your basic psychological traits, past experience, or knowledge push you to do. This could explain why some people show little facial expression on a regular basis.  It keeps them from feeling emotions.

The cognitive appraisal theory starts with the appraisal of the situation and then you pull up past emotions from past experience and find yourself in a particular emotional state. The second piece of this theory is that you can have a feeling without any cognition.  This would be like when you are surprised by that bear and you just run.  There is no time to notice emotion.

There are four qualities about emotions we must keep in mind no matter to which theory you subscribe.

  1. Emotions are expressed in stereotypical facial expression.
  2. Emotions are not always comfortable and we can choose whether we respond to them or not.
  3. Emotions change many cognitive processes, such as goal setting, decision making and personal relationships.
  4. Some emotions are hard wired in the brain. An example of a hard wired emotion is crying in a baby.  When uncomfortable for any reason they are hard wired to show their discomfort by crying.  They do not need to learn how to cry or when to cry Toby, (Cosmides, 1999)

The Brain and Emotion

It is mainly the limbic system,  sometimes called the old brain or the animal brain,that is responsible for producing emotions.  The limbic system is the part of the brain that we have in common with animals that regulate our bodies without our thinking about it.  It keeps our heart beating, your lung taking in air and your stomach digesting food.  We do not think about doing this and many other things because the limbic system just keeps on doing it.  However,  in humans this is a connection that the needs the limbic system and the forebrain communicating.

It is this forebrain that the evolutionary psychologist is thinking about.  We know that your brain always learns and memorizes experiences with emotions of the moment connected.This is the process that is important here. In many ways, the evolutionary psychologist sees the brain much like a computer with many different programs working together. There are two levels of circuitry. There is a level that controls cognitive process and then there is a superordinate level.  The problem with the first level of cognitive processing is that several of these programs contradict each other so superordinate programs must be available for support. For example, the program that says you should sleep now contradicts the need to run (fight or flight) when you see that bear.  Therefore, you need a subordinate program to mediate the situation.

According to this theoretical framework, and emotion is a superordinate program whose function is to direct the activities and interaction of the subprograms governing learning, memory, goals choice, motivational priories, categorization and conceptual frame words and psychological reactions  (heart rate, endocrine function, immune function, gamete release), reflexes, behavioral decision rules, motor systems, communication processes energy level and effort allocations, affective coloration of evenings and stimuli, recalibration of probability estimates, situation assessments, value and regulatory variables (self esteem, estimations of relative formibability and relative values of alternative goal states and efficacy discount rate), and so on (Lewis, Haviland-Jones, 2000).

Affective Coloration of Events

This is the major understanding that influences evolutionary psychology.  While the above process is very complicated we must remember that every memory that is stored is first “colored” by emotion.  Then remember that information only enters the brain through your five senses.  Everyone’s body is different and no two people can be in the exact same location at the same time so the information that is sent to the brain is first bias by difference in our senses physically, then colored by our individual emotion at that moment and then it is stored.  Now it begins to make sense why two people can be in the same place at the same time and see two different things and remember the event completely differently—-and both are right according to their body make up —-and both are wrong because  the body makes up bias.

The Evolutionary process – Adaptation

The way in which this all works together is the evolutionary process.  We have basic biological responses to situations including your senses sending information to the brain. Then there is the natural physiological responses to them such as the release of hormones, and finally there is a first response behavior followed by possible modulation by the superordinate programs.  With each experience, additional information is recorded and stored making more informed superordinate programs or additional programs.  This is a process of learning that evolutionary psychologist consider to be an evolution of brain function. This is the adaptive process of evolution. To postulate long term, the folks that do the best job of this process are the most likely to survive and pass on genetics.  That genetics may not be this exact information but it is the genetics that set up the ancestors to be successful so over time changed should be recorded genetically.  So far, scientists are convinced that the concept of natural selection is a strong force in the understanding of emotions.  The true evolution is the adaptation of the individual or groups of individuals.

It should be noted that there is one application for cognitive therapy that comes out of this information and that is the practice of emotional rehearsal. A client can walk thought an event, past or anticipated, and practice the emotion that they choose to experience either in a stored memory or in anticipation of and event. It is used in treatment of PTSD clients and in emotional control clients.


Lewis, M & Haviland-Jones, J. (2000). Handbook of emotions, 2nd Ed. New York, NY: Guilford Press.

Tooby, J. & Cosmides, L. (1999).The past explains the present: Emotional adaptation and the structure of ancestral environments. Ethology and Sociobiology. 11, 375-424.