Evolutionary Psychology, Logic, and Chocolate!

From the Lecture Series: Redefining Reality: The Intellectual Implications of Modern Science

By Steven Gimbel, Ph.D., Gettysburg College

Evolutionary psychology explains many things, from people’s love of chocolate to their habit of gossiping, to their behavior under different circumstances. Many of the illogical human behaviors look justifiable and understandable when viewed from an evolutionary psychology standpoint. Read on to find out what forms the core of this branch of science.

Hungry woman trying to steal cookie from mouse trap.
People do not need so much sugar and fat, yet, they love chocolate since it is an inherited craving from humans’ ancestors. (Image: ronstik/Shutterstock)

Most people love chocolate. Interestingly, many of them know well how bad sugar and fat are for health. Yet, they love chocolate and eat it. Why? Why does evolution do nothing about it when we can survive better without chocolate?

Brain Cravings

There is a biological reason for loving chocolate. Humans did not eat regularly, and they had to struggle to find food. When they needed to hunt for food, a rich source of energy and calories was very welcome, and fatty and sweet means a lot of calories.

Man picks plate of food from the fridge.
No matter how much a person knows about dangers of having too much sweets and chocolate, they still crave it. (Image: Lucky Business/Shutterstock)

Thus, the brain was trained to crave sweet and fatty things. Eventually, people learned to get food more easily, store it, and even have abundant food. However, the brain is still trained to look for sweet and fatty things and want them. It takes a long time for evolution to change a complex and critical organ like the brain. What else have humans inherited from their ancestors?

Structures, Functions, and Chemistry

Like taste preferences, other human behaviors can also have biological bases and evolutionary explanations. The bold sociobiological perspective in psychology explains human actions in terms of neurological structure, function, and chemistry. The question is, why do humans have these structures, functions, and chemistry?

The brain was formed through a long evolutionary process. The complexity of behavior associated with the complexity of the brain was a critical element to the survival of earlier humans. For example, in the case of chocolate, smarter human ancestors found out that flowers and early versions of chocolate could be very good sources of energy. Perhaps, some of the humans’ non-cognitive behaviors are also explained through the theory.

Evolutionary psychology emerged as a scientific field built around behavioral remnants of humans’ historical journey as a species. There are three core facts in evolutionary psychology.

This is a transcript from the video series Redefining Reality: The Intellectual Implications of Modern Science. Watch it now, on Wondrium.

Universal Behaviors, Desires, and Reactions

The first fact of evolutionary psychology is that there are some universal behaviors, desires, and reactions, regardless of culture and race. They are so common worldwide that they cannot have evolved from social contexts alone.

Gossiping is one of these universally common behaviors. It is beyond impossible that all cultures in the world came up with the same social behavior, so it must be a part of human nature and inherited from shared ancestors.

Learn more about brain and self.

Context-Specific Elements in the Brain

Another fact is that there are some elements in the brain that are context-specific and are designed to do very particular things. A person might do one task perfectly in one context and awfully in another. A very famous example of this is Wason cards.

In the late 1960s, British psychologist Peter Cathcart Wason developed a logic problem with cards to see how well people could solve it. Humans are proud to be logic-oriented smart creatures, and Wason wanted to know if the pride has a valid reason.

The problem was simple. Each participant had to take four cards which have numbers on one side and letters on the other, place them on a table so that one of the cards is showing an even number, one of the cards is showing an odd number, one is showing a vowel, and one is showing a consonant. Next, they had to find out if the following sentence was true, through flipping around some cards:

“If a card has an even number on it, it has a vowel on the other side.”

Surprisingly, less than 25% of the participants, and sometimes as few as only 4%, figured out what to do. They needed to flip around two cards, i.e., the even number and the consonant. It looked like humans were not essentially logical creatures.

Learn more about the birth of sociology.

Wason Cards: A New Context

Question mark on wooden desk background. Concept for confusion, question or solution.
The right context makes logic work very well, while the same problem in a different context might look impossible to solve. (Image: Natasa Adzic/Shutterstock)

Evolutionary psychologists Leda Cosmides and John Tooby placed the test in a new context: finding a cheater. Their four cards were slightly different: one with a person aged over 21, one under 21, one with an alcoholic beverage, and one with a non-alcoholic beverage. Participants had to see if there was any underage drinking going on.

This time, about 65-80% of the people did exactly what they had to. The conclusion was that the brain is designed to accomplish certain kinds of tasks with logic.

Learn more about genes and identity.

Mitochondrial Eve

The third fact in evolutionary psychology is that all humans have the same small group of ancestors whose brains had a sudden increase in size. Australopithecus afaren was the first human ancestor to have split off from the evolutionary lines of the other great apes in Africa, about four million years ago.

It took the ancestors a long time that until about 250,000 years ago, Homo sapiens, the early humans, emerged. The roots of humanity go back to a single great-great-great-great-great-great-grandmother, called Mitochondrial Eve.

Evolutionary psychology explains what we have inherited from Mitochondrial Eve and why we have certain behaviors against today’s survival rules.

Common Questions about Evolutionary Psychology

Q: What can explain human actions?

Human actions can be explained in terms of neurological structure, function, and chemistry. As evolutionary psychology puts it, the human brain gained enough complexity through evolution to form these aspects.

Q: Is gossiping a cultural habit?

No. People all around the world gossip. As evolutionary psychology explains, it could not be so widespread if it was not something built into human nature.

Q: Are people logical by nature?

No. A study in the field of evolutionary psychology that wanted to see how justified humans’ pride in being intellectuals is, found out the participants did poorly on a very simple logical task with cards.

Keep Reading
Unpacking Human Behavior: The Gene-Environment Correlation
Evolutionary Psychology and Fundamental Human Needs
How Evolutionary Psychology Informs Behavior