Sapiens – A Brief History of Humandkind // Notes

This is not a regular blog post by me, but the start of me sharing book notes. Noting down interesting points and train of thoughts while reading has always been something I wanted to start. This here comes with three simple motivations: 1) an exercise for me to keep notes, 2) a source I can access from everywhere and 3) sharing the points I find valuable with others.

This is about: Sapiens – A Brief History of Humankind by Yuval Noah Harari


– it is false to think there was a linear line of which humans existed and one has always been a better version of the previous one

– in the time period of 2m until 10,000 years ago, there were many different species of humans living on this planet

– the most durable version was the homo erectus ‘upright man’ who wondered the world for 2m years. This record is likely to be unbroken for a long while (not sure if we are here more than some thousand years from here)

– brain accounts for 2-3% of total body weight, but consumes 25% of the energy when your body is at rest

– walking straight came with a lot advantages like being able to scan the environment from a higher view point or using our hands, but also came with downsides

– upright gait requires narrower hips; combined with growing heads of children death in childbirth became a major problem

– over time nature adjusted and babies are born prematurely

– hunting and taking care of a baby that is absolutely helpless is a hard job nowadays, but also for the women back then. Thus, raising a human was always a group activity

– this is one of the reasons for our ability (and maybe even desire) for building such strong social ties

– arriving to this earth rather prematurely our species has the rare position to be able to educate and socialise the baby in whatever way one wants, i.e. to be part of a specific religion

– for a long time human were not high up the food chain, but constantly needed to look out for predators

– one of our first tool niches was apparently when we needed to crack open bones to get to the marrow – which was the only thing left after lions, hyenas, jackals, etc.

– 400k years ago we started to hunt bigger animals, and especially with the raise of the homo sapiens 100k years ago we jumped to the top of the food chain

– with this fast jump and not gradually growing into this position over millions of years, the ecosystem has not been able to adopt to the new ‘king’ and develop checks so we don’t wreck too much havoc

– i.e. as lions became deadlier, gazelles evolved to run faster, hyenas to cooperate better, and rhinoceroses to be more bad-tempered

– not only did the ecosystem not have time to adjust, also humankind failed to adjust themselves

– previous predators had million of years to develop self-confidence in their abilities and position and evolved to be majestic creatures

– sapiens are more like a banana-republic dictator (<= love that quote)

– having recently been an underdog we are full of fears and anxiety over our position which makes us doubly cruel and dangerous

– game changing to make the leap to the top was the use of fire. By 300k years ago, human species likely used it on a daily basis.

– clear advantage to have light, stay warmth in cold times, deadly weapon against lions, be able to expand food choices to things we are not able to digest in raw form (i.e. rice, potatoes) + fire killed gems + time saver (chimpanzees spent chewing raw food 5hrs a day)

– more food brings more energy and the fact it is cooked makes it easier to digest => smaller intestines & bigger brains

– homo sapiens have their origin in Africa

– there are two theories for the time when they moved to new continents: ‘Interbreeding Theory’ (apparently their is evidence of Neanderthal DNA in Eurasia humans) or ‘Replacement Theory’.

– due to better technology and superior social skills of homo sapiens were better hunters, it might be that Neanderthals simply extinct due to the lack of natural resources for them

– another theory is that it might be the first case of genocide (as we have proven to not be tolerant to others who are too familiar to ignore, but too different to tolerate)

– how would life be if there is actually another species like ours? Would ever ‘homo’ have the same rights?


Three of knowledge

– the homo sapiens already tried to invade Neanderthals territory before, around 100k but failed.

– on the second attempt, around 70k they managed

– not only that within the time period of 70k to years ago, they invaded Middle East, extinct Neanderthals and crossed the sea to Australia due to inventions of boats, oil lamps, bow and arrow and the needle (important for clothing)

– this change in our behaviour and skills is called the cognitive revolution

– apparently our brain experienced an accidental genetic mutation which enabled us to think in unprecedented ways and to communicate in a new language

– this language aspect might have been the key

– some animals have even more sounds than us available to communicate, i.e. a parrot can basically say everything we say + do a lot more sounds

– but sapiens managed to arrange our limited sounds to come up with an infinite number of combinations with a distinct meaning

– as described, homo sapiens have always primarily been social animals

– the language advantage was not used to talk about lions, but for gossiping

– in a group of 50 humans, there are 1,225 one-to-one relationships. You wanted to know who is cheating, who is hating who, who is honest, and who is cheating.

– with that information and knowing who can be trusted, we were able to form much tighter and more sophisticated types of cooperations

– however, the most unique thing about our language is the ability to transmit information about something that does not exist at all, fiction and stories

– apes are know for living in groups for up to 50 members, above stability decreases

– just like politicians a new opponent wins members by giving favors, hugs and interaction with others. After all, the leader of a group is responsible to run a stable coalisation

– for humans that size is said to be 150, due to our ability to talk and gossip

– movements or corporations with more people need some sort of common beliefs to still function, as one won’t know everyone on an intimidate level

– when two states fight about a topic for which each of them has a different law, does this law really exists or is it rather a fiction made up to align a specific group of people?

– as time moved on, imagined reality became more and more powerful than actually talking about a lion near the river

– due to the power of this, large scalre corporations and the common language can be altered and recalibrated which makes humans highly flexible and adapt to new circumstances by rewriting the story and revise behavior in accordance with changing needs

to be continued