Emotions are not some mysterious processes that have no explanation.

As all nervous signals in our body are bio-chemical, emotions are bio-chemical algorithms optimized by millions of years of evolution.

Yuval Harari brings forward the following example.

A hungry baboon hidden in the bushes sees the banana tree. However, near that tree, he sees a lion.
So, the baboon needs to make a statistical calculation operating many important parameters.

How many bananas on the tree and how ripe they are.
Is the lion hungry or he just ate and is ready to sleep?
Is the lion experienced or this is still is overgrown cub?
How hungry the baboon itself? How fast he can run? And so on.

Obviously, the baboon doesn’t possess the intellectual apparatus allowing him to make these calculations. However, he doesn’t have to.

That’s where his biochemical algorithms work. If the probability of success is less than 50%, the baboon experiences the emotion of fear and leaves. On the contrary, if the probability of success is above 50% it is manifested in the emotion of courage, and baboons run to the tree.

The human brain and human emotions were formed and optimized by millions of years and most of these years, humans spent hunting and gathering.

They started using their brains in a different “human” way only the last 40-50 thousand years, which is a tiny percent of their conscious history. However, during this last period and especially during the last 10 thousand years there was a gigantic change in human lives, to which human bodies and human emotions were not optimized.

For example, why do we want to eat much more than what we need?

Because, during hunting and gathering times, food was scarce, and sometimes people had to roam around hungry for several days before they could have a real meal. That’s why when there was food in abundance, they ate as much as their belly allowed and still haven’t been obese. Nowadays, the lifestyle of people completely changed. They sit in the office all day and hit the buttons on the keyboard. But their bodies still have the urge to eat as much as they can because that is how it was optimized by evolution.

Similarly, the mechanism of stress is something that helped people to make a quick decision at the moment of meeting with a large predator or grass-eating prey. Hence, fight or flight reflex, and stress hormones that raise blood pressure to pump more blood to muscles so a person can run away or fight.

The human body is not designed for the modern type of stress: intellectual and emotional stress at work, recession in the economy, sceneries of earthquakes, floods, concentration camps, mass murder, and such. The level of stress is high, blood pressure rises but there is no immediate danger. A person doesn’t have to be engaged in an immediate physical activity: run or fight. That’s why cardiovascular diseases are the number one killer.

Coming back to emotions, human emotions are also not designed for the complexities of modern life. They are also designed and optimized for survival and perpetuation of one’s species for the conditions of hunting and gathering.

That’s why men are such “dogs” and would stick it in into anything that walks and has a hole. Their natural desire is to spread their seed to as many carriers as possible. That gives them more chances of perpetuating their genes to future generations. But sperm is cheap, while the egg is expensive and a woman, who has to carry the child and care for them for a long time, chooses a male that can better protect the egg during incubation and subsequent care.
However, modern life imposes so many limitations of both genders that emotions are no longer capable to properly serve their ultimate purpose.

Emotions tell a woman to pick stronger and taller male with symmetrical features – the sign of good health. Instead, there are a bunch of new considerations that now have to be handled by a small part of the brain that gets its full development only in the last 40 thousand years. That’s why emotions are so convoluted and people have difficulties understanding themselves and have nervous breakdowns, and had to go see psychologists just to understand themselves.