Although there are many thinkers and philosophers who have considered man as a wolf for man, or who have displayed an individuality and a desire for hermitic watchmen far from others, the truth is that science tells us fair the opposite: the human being makes the best of himself if he is with other human beings, and the normal thing is that absolute loneliness be our worst enemy.
While the first human beings, as with our cousins, the great apes, lived in small groups, deploying a deep xenophobia for strangers, progressively we have become increasingly global citizens.
As communities, throughout history, increased in size, people had to overcome their natural instinct to lash out at others. Some theories point to the economic transaction and commerce in general as facilitators of that first step of connection with strangers. As he points out Marcus Chow in his book The universe in your pocket:
It is likely that natural selection intervened in this field as well. Those settlements whose inhabitants best knew how to live in that mutual closeness without large outbreaks of uncontrolled violence were those with the lowest death rates and, therefore, those that grew faster than others. Their numerical predominance meant that, over time, people became more passive and tolerant of each other.
This thesis is also defended by the cognitive psychologist Steven Pinker in his book of almost a thousand pages The angels we carry inside.
This inclination to be with each other has also minimized violence and belligerence. To the point that people now like to be with other people: look at the big cities, the overflowing coffee shops, the shows and discos where even the interpersonal distance disappears.
And the writing came
If, when we dominated the fire and the kitchen, it was as if we had an extra stomach that allowed us to more easily ingest the amounts of calories required by an increasingly large and complex brain, the arrival of the writing functioned as an external memory and, at the seasoning, a way to collectivize populations:
If, orally, it was only possible to transmit a reduced volume of knowledge, in writing, that volume grew exponentially. Thanks to writing, the human race acquired a collective brain. To wake him up completely, we had to wait for literacy to spread across broad layers of the population, which took many millennia to occur.