"You will become way less concerned with what other people think of you when you realize how seldom they do."― David Foster Wallace
Our ancestral past made us care what other people think. It was nature's way of adapting our species to the environment. So we became fiercely egalitarian hunter-gatherers that lived together in small groups. Imagine living with a tribe of humans, say 30-50, your entire life.
Then imagine no personal property. No ideas around marriage or ownership or hierarchy whatsoever. No money. That is the way of life our species is designed for.
The humans we lived with daily our entire lives kept us from slipping too often into the ugly side of our nature—greed, jealously, war, betrayal, etc.
Many observed hunter-gatherers still living a similar way of life today have been observed with this fiercely egalitarian—everyone equal—way of life. Rituals for resolving conflict might include violence or some competition or group discussion. Shame was a hand tool for hunter-gatherers to make sure everyone's ego is always kept in check.
And contrary to a misconception of our ancestors being "cavemen," hunter-gatherers lived long and healthy and functional lives without the sickness of body and mind we have in our modern environment.
Then we started farming, and everything changed.
Personal property led to warfare to protect our own property (our food supply) and eventually or conquer other's property (their food supply).
Civilization led to money, commerce, and all the advancements of civilization, which are awesome, but which have come with an ugly byproduct: humans can now lead private lives in which there is little social collaboration to keep our behavior in check.
This mismatch of the environment is the core root of every problem of humanity we struggle with today. Every. Single. One.
The first step for you, the individual, is to understand your evolutionary past to make conscious decisions to combat the biological drives that can lead you to overconsumption and excess. Unlike the rest of the animal kingdom that operates through base drives programmed through nature, humans possess the ability to CHOOSE what we do through the miracle of consciousness.
Generally, humans want to help and do good because this is programmed into our species. It's one of nature's greatest gifts to humanity and is the result of our need to raise offspring for years on end outside of the womb. Without a strong enough emotional connection, our species would not have been able to protect our fragile-outside-the-womb-offspring for years until our children were old enough to fend for themselves. This happens to be one of our great differentiators from other animals in the animal kingdom—many animals come out of the womb, ready to eat, walk around, climb. In contrast, human infants are 100% reliant on mother to survive. And after that, it still takes years for a growing human child to be fully self-sufficient in a wild setting, thus the biological drive for all humans to protect our young.
Love is a natural mechanism built into our species designed to keep us protecting our group, especially our young.
The inverse is fear and hatred rooted in tribalism, which just so happens to have been another way nature kept our species safe. Any human outside your group in the wild is a potential threat. And the more likely they are to look different from you, the more likely they are to be a threat. This is why the fear of different is hard-wired into our species, especially "different humans." It's also why we tend to coalesce into groups of people that think and look like us, and in today's age, that have a similar economic status.
Yet most people have little understanding of human biology, and specifically of how evolutionary biology and psychology are the first principles framework for understanding everything pertaining to humans.
Scientists study chimpanzees in their natural environment to better understand chimp behavior and biology. Yet science has taken a different approach to understanding humans due to generations of religious dogma, making humans god-made creations above the animal kingdom. This has stifled attempts to understand human behavior since even the suggestion that we can understand humans by studying them was considered blasphemy.
Thus you can find countless examples of science covered up, repressed, or ignored when sharing inconvenient findings related to societal-sensitive topics like sex, violence, racism, rape, murder, and so on.
That approach is a sure-fire path to getting MORE of the bad behavior we should desperately be trying to understand. Only through understanding our human nature can we evolve out of these build-in biological tendencies.