Two Instincts and Three Abilities
All human emotion is caused by an interaction of five evolutionary traits of humanity.
First are the two evolutionary instincts shared by all animal species: survival and reproduction. In effect, those are just two different versions of the same instinct: The instinct to preserve the survival of your DNA by the most effective means perceivable to you.
The other three are the three basic mental abilities that combine to form human intellect, which enable us to perceive things that other animals can’t. People have the ability to imagine abstract ideas, to perceive the passage of time, and to communicate abstract ideas among members of the species. Other animals have these abilities to some degree, but humans have a clear advantage in all of them over all other species.
As Dr. Andrew Newberg and Dr. Eugene D’Aquili explain in their book Why God Won’t Go Away, animals’ instincts can only be triggered by direct stimulation of their senses—the sight of a predator or a potential mate, for example. Humans’ instincts can be triggered by direct stimulation, but also by things they can imagine, things they can remember, or things they’ve heard about from other humans. (Technically these things also apply to other animals to a lesser degree, but again humans have a clear advantage over all other animals here.)
Any time you, or anyone else, feel any emotion, you are reacting to something that involves either your survival or reproduction (or both). You are reacting that way because of direct stimulation to your senses or because you imagine something, you can remember something, or because you’ve learned about something from someone else. Of course you can be doing any number of those things and any combination of those things all at the same time, and some of them could be conscious while others are only subconscious. The possible outcomes are virtually infinite, but all of those infinite possible outcomes originate from those five mental characteristics.
For instance, if you were walking through a forest and you knew grizzly bears lived there, you would feel afraid. You would be alert for grizzly bears and for signs of grizzly bears. You would be ready to run away if you saw a grizzly bear or any indications of a grizzly bear.
You would feel afraid because you had seen what grizzly bears did to someone else, or because you’d heard what grizzly bears did to someone else, and you could imagine what a grizzly bear would do to you.
If you saw something moving in the bushes, you could imagine it was a grizzly bear and react as if it was a grizzly bear, by dumping lots of adrenaline into your blood and running away.
That would give you a big head start over someone else who waited to see the actual grizzly bear before running away. It wouldn’t matter if it was only a squirrel in the bushes, because by imagining it was a grizzly bear and running away, you preserved the survival of your DNA just the same. As the saying goes, better safe than sorry.
A deer walking through the same forest would only have his “natural fear of everything” to protect him. If he saw something moving in the bushes, he would only perceive it as “something moving in the bushes”; he wouldn’t imagine it was a grizzly bear. He would stop whatever he was doing, look over, wait to see if anything happened, and if nothing happened, he would go back to whatever he was doing. The only way he could learn to be more afraid of grizzly bears than he was already would be by surviving an attack by one.
Deer and grizzly bears are able to compete against each other as species because deer can run about as fast as grizzly bears. Sometimes the deer win, and sometimes the bears win.
Humans can’t run as fast as grizzly bears, so we depend on other abilities to make up the difference. By imagining that something moving in the bushes could mean a grizzly bear was coming, instead of running faster, we run sooner.
The deer fears the bear. The human fears the idea of the bear.