Sapiens Summary

• The best thing fire did was cook.
• Cooking killed germs and parasites that infested food.
• The advent of cooking enabled humans to eat more kinds of food, to devote less time to eating, and to make do with smaller teeth and shorter intestines.
• Whereas chimpanzees spend five hours a day chewing raw food, a single hour suffices for people eating cooked food.

• You could never convince a monkey to give you a banana by promising him limitless bananas after death in monkey heaven.
• But why is it important? After all, fiction can be dangerously misleading or distracting.
• People who go to the forest looking for fairies and unicorns would seem to have less chance of survival than people who go looking for mushrooms and deer.
• And if you spend hours praying to non-existing guardian spirits, aren’t you wasting precious time, time better spent foraging, fighting and fornicating?

In the food chain, humans were supposed to be on the level of monkeys. The ability to adapt without any change in the DNA is what made humans superior to any other animal. But such a sudden rise in the food chain without proper evolutionary development led humans to be always afraid and insecure in the back of their minds, similar to how monkeys are afraid of their predators.

The power of fiction and gossip led humans to collaborate on a massive scale. But beyond a group of 30 people, we cannot completely understand other people. Hence, humans have an evolutionary tendency to gossip about other people, to find out if they are safe and could be trusted.

Humans didn't domesticate wheat. In terms of evolution, it is wheat that domesticated humans. Humans became slaves to crops, tending to them every day, increasing their population, even at the cost of their aching backs.

From a biological perspective, nothing is unnatural. Whatever is possible is by definition also natural, a truly unnatural behaviour, one that goes against the law of nature, simply cannot exist, so it would need no prohibition. 

The most important finding is that happiness does not really depend on objective conditions of either wealth, health or community, rather it depends on the correlation between objective conditions and subjective expectations, like, if you want a bullock cart and get a bullock cart, you're content, if you want a brand new ferrari and get a second-hand fiat you feel deprived.

According to Buddhism, the root of suffering is neither the feeling of pain nor of sadness nor even of meaninglessness. Rather the real root of suffering is this never-ending and pointless pursuit of ephermal feelings, which causes us to be in a constant state of tension, restlessness and dissatisfaction. Due to this pursuit the mind is never satisfied. Even when experiencing pleasure, it is not content, because it fears this feeling might soon disappear, and craves that this feeling should stay and intensify.

Humans are storytellers – 70,000 years ago, we developed the ability to imagine and share stories, which helped us cooperate in large groups.

Fiction built societies – Myths, religions, and ideologies united people and created shared beliefs, enabling civilizations to form.

Language gave us power – Our ability to communicate complex ideas made humans the dominant species.

Over the years, people have woven an incredible complex network of stories. Within this network, fictions not only exist, but also accumulate immense power. The kinds of things that people create through this network of stories are known in academic circles as fictions, social constructs or imagined realities. 

Fiction helps us not merely to imagine things, but to do so collectively. Such myths gives us the unprecedented ability to cooperate flexibly in large numbers. 

Diprotodon is an extinct genus of gigantic quadrupedal marsupial native to Australia during the Pleistocene epoch. Diprotodon meaning in Greek "two forward teeth". The genus is currently considered monotypic, containing only Diprotodon optatum, the largest known marsupial to have ever existed

Neanderthals are an extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago. They most likely went extinct due to assimilation into the modern human genome, great climatic change, disease, or a combination of these factors.

The main difference between Neanderthal and Homo sapiens is that Neanderthals were hunter-gatherers whereas Homo sapiens spend a settled life, producing food through agriculture and domestication.

Mammals Weighing 60 kilograms have an average brain size of 200 cubic cms. Modern sapiens averaging 1,200 - 1,400 cubic cms. Neanderthals brain size was even bigger.

In sapiens, the brain consumes 25% of body’s energy when the body is in rest. While comparing with apes it is high, who consumes only 8% of energy in rest.

Women who gave birth earlier was able to survive because of the child’s small brain and head. Death in child birth was higher when the size of the brain and head increased.

The Cognitive Revolution represents the critical mutation that launched our species' dominance. This evolutionary leap enabled:

• Flexible cooperation with unprecedented numbers of strangers
• Creation and belief in shared imagined realities like gods, nations, and corporations
• Formation of communities larger than the ~150 individuals our brains evolved to track
• Development of constantly changing social norms without requiring genetic evolution

Unlike other animals limited to objective reality, Homo sapiens inhabit dual reality—the physical world and a symbolic one of shared imagination. This symbolic reality grows more dominant as civilization advances, with most modern human behavior driven by fictive constructs that exist purely through collective belief.

The Agricultural Revolution represents a Faustian bargain that transformed human existence. Contrary to progressive narratives, this shift brought multiple regressions:

• Narrower diets dependent on few crops, causing nutritional deficiencies
• Crowded conditions ideal for spreading infectious diseases
• Longer, harder labor compared to foraging
• Vulnerability to crop failures and resulting famines
• Emergence of hierarchy and systemic inequality

From the crops' perspective, wheat, rice, and corn manipulated humans into expanding their territory. The gradual transition prevented any generation from recognizing the trap until escape became impossible.