The more traditionalistic dogmatic views on human nature see the human being as a “near perfect” reasoning machine. Two of (western) society’s most prevalent mantras, namely religion and economics, create a framework of expectations that quite often are not met. Research in psychology and simple daily life observed under critical lenses challenge these assumptions.
One extreme interpretation of the psychology view on human nature would be that humans are completely irrational. As any extreme perspective it is, in my opinion, wrong. The “truth” is that we are neither perfect rational agents nor dumb mindless creatures.
In order to get a better understanding of human nature, my suggestion is to start from the beginning of human kind. If you have a creationist view, then you are free to stop reading. If you accept evolution theory, however, please keep reading.
Our (extremely) distant ancestors faced quite different problems than we face now. They have adapted from generation to generation to survive and successfully reproduce in a very different context than the one represented by the modern world.
One of our distant ancestors’ main concerns was to get metabolic resources or in other words highly nutritious food. Evolution shaped the human brain to perceive sweet and fatty foods as tasty. The wide majority of people likes sweet stuff and (up to a point) fatty food. Eating as much sugar and fats was very useful for survival, especially because these nutrients were very scarce. In our world, however, sugar and fats are abundant (at least in some wide geographic areas). What was evolutionary useful for most of human kind existence is now detrimental.
One million years ago if one of our ancestors would eat all the sugar and fats she could get her hands on it would have increased her chances of survival and of having healthy children. Today if a lady (or a man) eats all the sugar and fats she can get her hands on it would make her more susceptible to diseases and it would make her fat and subsequently considerably less attractive for men (women), thus decreasing her chances of having healthy children.
In today’s world we have to exert self-control in order to NOT eat too much sugar and fats. This is completely opposite to our instincts and natural drive.
The sugar and fats example is only one of many mismatches between what humans have evolved to be and what humans should do in the modern world.
And… NO! I do not advocate in any way that we should return to the “stone age”.
Not everything that evolution has shaped us to be good at is outdated in the modern world. For example fear is still quite important to ensure survival. Most humans are “hard wired” to fear fire or in other words we are inherently afraid of fire. This was extremely useful for our distant ancestors’ survival and even in the XXI century it works quite the same way. If there’s a fire, RUN!
One particular thing that we are very good at is to detect “high quality” potential mates. What is generally accepted as (sexual) attractiveness features are in fact signs or cues of general and reproductive health. Finding an “as good as possible” (life) partner with whom to have children is still highly important even in the year 2012. Indeed, modern medicine increases the infant’s chances of survival, but good genes from healthy parents are still extremely important.
Let’s take a step back and go to the “Dual-System” model of judgment. We have the “Bird brain” (system 1) and the “Computer brain” (system 2).
The “Bird brain” is older from an evolutionary perspective. My best guess is that thinking with the “bird brain” is reasonably effective in achieving the evolutionary macro-goals of survival and successful reproduction. These macro-goals lead to more detailed goals such as getting enough food, attracting potential mates and so on. My view is that overall System 1 can do all these things well enough.
If the “bird brain” works good enough to ensure the achievement of the fundamental goals of life, then a legitimate question arises, namely why do we have the “computer brain” (system 2).
Now, this question is very deep and complex. In no way I claim that I can give the complete answer to it, but I will try to give a reasonable explanation. Let’s take a look at the characteristics of judgment performed by the “computer brain”. When I described the “Computer brain” I wrote: “The “computer brain” is slow and analytical. It bases its judgments on rules acquired through culture or formal learning and tries to identify structures in the environment.”
From an evolutionary perspective the results of thought processes performed by system 2 would be advantageous, but not vital for achieving the Macro-Goals of survival and successful reproduction. Let’s leap in time about 2 million years ago. Our ancestors were living in small communities under the constant threat of predators and of hunger (lack of sufficient metabolic resources).
Imagine that in a community some of the (pre)humans had some judgment capabilities specific for the “computer” brain. These (pre)humans would be able to defend their community slightly better than (pre)humans in other communities. Similarly, they might be able to hunt better or to get better fruits and vegetables. In evolutionary terms these slight advantages mean a lot.
Another view comes from the evolutionary psychologist Geoffrey Miller (author of “The mating mind”). Miller claims that the human brain as we know it has evolved through sexual selection. In more simple words, the (pre)humans who showed signs of higher cognitive capacity would be perceived as more attractive by the opposite sex and thus would have better access to high quality mates and had more and better offspring. I really recommend reading Geoffrey Miller’s books for more details on this.
To summarize, the “Bird brain” is reasonably good at fulfilling the evolutionary macro-goals of survival and successful reproduction. The “computer brain” is useful at increasing the level of achievement of the aforementioned goals. In other words, if a person relies only on “Bird brain” judgment, then he or she has reasonable chances of survival and having children that will have children of their own. If in addition to the “bird brain” judgment a person uses (some) “computer brain” judgments the chances of surviving and having children that have children of their own will increase.
Taking this view, I believe that it is clear that human judgment doesn’t need to be fully rational. If what we were designed for – survival and successful reproduction – can be achieved without perfect rationality, why assume that people are fully rational? Making rational judgments increases the chances of achieving the evolutionary macro-goals, but it is not necessary.
From a (social) market perspective, making use of the “computer” brain can give a competitive advantage for acquiring resources and potential mates. At the same time, not using the “computer” brain does not necessarily lead to exclusion from the social market and subsequently from the evolution mechanism.
Who knows, maybe in a million years from now evolution will lead to an improved human kind that will naturally make more use of “computer” brain judgments.
As an ending thought, we are not designed by evolution to function perfectly when it comes to deciding on pension plans, financial investments and many other things we encounter in modern life.