This, some evolutionary psychologists claim, explains perfectly well why modern-day humans are selfish: Through hundreds of thousands of years of evolution (according to the latest findings, Homo Sapiens is at least 300,000 years old), we’ve been biologically and psychologically programmed to behave in selfish ways.

This theory sounds plausible, until we take into account historical and archaeological evidence. Contrary to what most people think (and yes, that includes distinguished scientists too), for 99% of human history humans lived pretty much at peace with one another.

Before the Neolithic Revolution — that is, the wide-scale transition of many human cultures from a lifestyle of hunting and gathering to one of agriculture and settlement that took place some 12,000 years ago.

Humans lived mostly in nomadic, hunter-gatherer groups of up to 150 members. Back then, the world was sparsely populated (according to some estimates, the global population was no more than half a million around 15,000 years ago), food was abundant (at least, for the most part), and humans were quite healthy.

Therefore, it seems unlikely that they would fight against each other for resources, or for any other reason really. This doesn’t mean that they never did fight, it does suggest that they peacefully coexisted, without the need for competition and organized violence.

As humans were settling in agricultural societies, they gradually started to behave very differently compared to hunter-gatherers. They began to privately own land (which, by the way, was inconceivable to hunter-gatherers, who saw the land as a sacred gift of nature to be shared by all), as well as animals and other resources.

This, led to social and economic disparities between humans. Resources weren’t enough for everyone anymore, as they used to be until that point in time. Naturally, humans felt more and more compelled to act selfishly in order to survive and gain competitive advantage.

Fast-forward a few thousand years and the same competitive ethic exists to this day — and arguably more than ever before. Modern humans live in conditions of scarcity, where nearly everyone is forced to compete for money and resources.

In this world, we’re taught from a very young age that there are winners and losers — and if we want to be winners, we need to be very competitive. We’re conditioned to believe we can find succeed in life. Add to our materialistic culture where people are judged based on their possessions, it becomes crystal clear why humans today behave mostly in selfish ways.

“A false friend and a shadow attend only while the sun shines.” —Benjamin Franklin