Human stupidity
We are so stupid. If you don't trust me please switch on your TV and see the news. You can also read a history book. As Douglas Adams said in his book The Hitch-hiker Guide to the Galaxy: "Many [human beings] were increasingly of the opinion that they’d all made a big mistake in coming down from the trees in the first place. And some said that even the trees had been a bad move and that no one should ever have left the oceans."
We all humans tend to share the same ideas, depending on the culture and the time in history. A few centuries ago people were really worried about their honor. Now it is not that important, this has changed. If you had said to a man from the fifteenth century that honor is not important, he would have thought that you are a coward or bad in some sense. This behavior, the hatred of the different, has been always the same. And it is still the same nowadays. In North Europe and North America, fascists movements are growing and it is happening the same with communists movements in South Europe and South America.
This hatred of the different has been studied by many philosophers, psychologists and other scientists. Many of them agree that human beings are like sheep. The sheep is probably the most stupid animal in nature. If a sheep starts to move, all the rest follows. If all sheep are seated and one gets up, all of them get up. I really recommend you to go to the countryside and observe their behavior, it's really hilarious.
How human learning works
Generally speaking, we have two ways of learning, imitation and innovation. We imitate when we acquire knowledge from others. We innovate when we generate knowledge by ourselves.
It turns out that the most common way of learning is imitation. It is how children learn in their first years. It is how we acquire knowledge when we are in school or University. And it is also the main learning method during our careers. Imitation is so common in human behavior that a scientist suggested changing the name of our species from hommo sapiens, which means "man who thinks" to homo imitans, which means "man who imitates".
Imitation is also very common among animals. But a recent study showed that apes are more suitable to imitate while children show more tendency to over-imitate, in the sense that children make an attempt to improve the learnt skills. Innovation is therefore an essential part of human behavior.
There is a biological reason that explains why we tend to imitate rather than innovate. Imitation costs us less energy than innovation. Energy is the money of the Universe and nobody wants to spend their money.
Generalization
One of the main features that make us more intelligent than animals and machines is our ability to generalize. In fact, generalization is the only obstacle that Artificial Intelligence needs to achieve in order to surpass human intelligence.
We don't fully understand how the human brain works, but we have some ideas. We know that we create representations of our environment. These representations are flexible models of things together with their relationships.
Let's put as an example of the concept of a table. In our minds, a table can have many different shapes and colors. It can be used to place objects over it or to have lunch. All of us are able to identify any table without a doubt, even if we have never seen a particular one. This is because we have a flexible concept of what a table is.
This leads us to a very important feature of our intelligence, our ability to understand differences between representations. And we can identify them really fast. As an example let's say that somebody removes the computer from our room. We will be able to notice it instantaneously. What is really happening inside our heads is that we compare our representation of the room with what we currently see. But we don't analyze the room object by object, we just perceive that the computer is gone.
Therefore, we have evolved to be able to store little information of the representations, in a very flexible way. And at the same time, we are able to understand the differences between these representations very quickly. This is what makes us more intelligent than any animal or machine. But we have to pay a price for having our superior intelligence. We have to pay in energy.
The hatred of the different
Every time somebody tells you something that is not what you think, you have to spend energy. And that is why it pisses you off. It is cheaper to agree than to disagree.
That is why so many people tend to racism (here I use the word racism in a general way, in the sense of hating the different) because people are stupid and don't want to make an effort to accept the different. Imitation is easier than innovation. Imitation implies doing the same as other people say. Innovation implies making an effort to think different. There is a reason why there are so few innovators in this world and there is a reason why those innovators are rejected by the majority. The reason is energy.
To be honest, I don't know the solution to this. Maybe one possibility is scientific thought. Scientists reject imitation by default. We only accept what can be proved and confirmed by evidence. But maybe it is not the best solution.
Maybe it is time for all of us to admit that to some degree we are intolerant to what other people think and that we are not as smart as we think we are. Maybe it is time to deeply analyze our believes and start innovating instead of imitating. If we do that I'm sure that the radicalisms that we are experiencing will go down.