Evolutionary Psychology and the Human Brain

By: Dr. Susan Siegfried, Clinical Psychology

The human brain is complicated.  A basic look at the brain and its function is provided here with the intent of helping the reader understand how it all basically works together with the concept of evolutionary psychology. The brain itself is a part of the study of neurology.  It is part of your neurological system.  It is who you are.  You physically function, think, feel and remember with your brain.  All those things together form your personality; it is who you are. So you do not love someone with all you heart; you lover someone with all your brain.

Anatomy and Physiology

Your brain is basically neurons which work together in groups. These groups are formed through learning and experience.  A synaptic connection is a group of neurons that communicate together.  This psychologist tells her students that they are now forming a psychology synapse while sitting in and studying for her class.  All that means is, that neurons that have not been communicating before are literally moving together to collect and understand psychology. This is really our first look at evolution in the brain. When you were born you have very few synaptic connections.  You built them through experience mixed with your senses (everyone’s sensations are different because our bodies are different) which to a large degree is based on genetic. It is your synaptic connections that allow you to interpret these experiences and sensations.

You also have glial cells in your brain which clean and support the neurons as well as nourish and likely many other things of which we are not yet sure.  We do know that very intelligent people have many more glial cells than everyone else and about the same number of neurons as everyone else. This is a relatively new understanding of the brain so stay tuned as this writer suspects we are on the precipice of understanding much more about intelligence and how to preserve it as we age.

Parts of the brain

Your brain is separated into different parts or areas.  You motor cortex is on the outside of the brain.  The inner part of the grain is much the consistency of jello; the outer layer is more like a punch ball that contains the jello.  It is this punch ball area that is the cortex.  Unlike the punch ball  it has many many wrinkles in it.  The wrinkles develop over time because more brain area is necessary as you learn. This is another example of adaptation (evolution in the brain).  Your midbrain, hindbrain, pons, medulla forebrain and cerebellum are all responsible for different functions making you who you are. They are all working together so you function as you do. Each part changes over time. You are constantly making new synaptic connection. The study of human development integrates the neurological knowledge with learning and genetics to explain how we go from a seven pound helpless newborn to an adult.

How Does Evolution Apply to the Brain

There appear to be two forces responsible for the evolutionary process in the brain. This is the evolutionary process that brought us from the Neanderthal to what we are today. Adaptation comes in two forms (l) learning; that is if you figure out the best way not to get killed, such as grouping for protection. It also includes developing things on your body that you need such as (2) developing an appendage such as the opposable thumb to light a fire in the winter.  Developing means; taking something that is there and pushing it in a new way to do new things. Both of these things allow you to survive and those that do not attain them to die.  Your genetics goes on.  That does not necessarily mean that you learning how to use an underdeveloped thumb will go directly to your off spring but it is likely the will get that underdeveloped appendage to work and your drive to learn how to use it will likely be passes on. Also, your “thumb” appendage needs to be large enough to begin the process so it is likely that those with the larger appendage will be more likely to reproduce. Over generations the thumb will be usable at birth because of evolution.

The evolutionary approach says that the simply explained adaptation above also affect things like sexual conflict, mating, sexuality, families, social conflict, aggression, morality, depression and anxiety. That is a long list. Let us take one as and example.  If you happen to be a very anxious individual, one would expect you would spend more time than average getting thing as perfect as possible, or go the opposite way and shut down.  If you were in a large group of people who had to cross a freeway everyday to get to work you would likely hang back and shut out the noise and not see the cues to keep you from getting hit and be killed; or you might be so compulsive so you would never find a time to cross the freeway and lose your job and starve to death.  Your genes will not go on. The people who are sure of them self, yet careful individuals will pass their traits on. Your “shutting down” anxiety or “compulsive’ anxiety will be lost.

It gets even better, because this adaption happens even in our life time through learning, which changes synaptic connections so you do better in life.  You biologically reproduce and pass on the willingness and ability to adapt and learn. Neuroscience and evolutionary science are helping us understand how all this works in the brain which helps science teach us how to be better by passing on the helpful genes. We also learn how better to treat mental health disorders.  We will see aggression looked at carefully in the near future.  How do we change, by learning now eventually becoming an evolutionary change, the aggressive individual and how do we change our cultures aggressive turn?  The answer is likely at least partially in evolutionary psychology.