[eli5] Why did humans advance so far so fast while other intelligent animals did not?
In: 944
Because as far as we know there are no other animals with our level of intelligence.
Even other apes, which are very closely related to us, are no better than young children when it comes to intelligence. You don’t get a lot of average intelligence children building rockets that fly to the Moon.
If you only look at the past few thousand years then sure, we developed extremely fast, but you’re then ignoring the millions of years before that. We’ve had fire for a million of years, stone tools for 2.6 million of year, and civilisation only came about maybe 10,000 years ago.
The fact that we developed civilisation when we did is due to a factor of our intelligence, luck in our biology (elephant and dolphins are extremely smart, but don’t have the bodies for tools and fire) and a whole lot of time.
An intelligent species may not always lead to civilisation if other factors don’t align for them
Eating protein, specifically protein cooked in fire, provided a substantial boost to our brain development. Cooking animal protein in fire allowed our digestive system to more readily absorb nutrients. Raw food is not broken down enough by the time it reaches the large intestine, where the lions share of the nutrients are then consumed by the microbes and bacteria living there. However cooked meats are broken down inside the stomach and small intestine sending valuable building blocks to the brain.
To add to other comments, our ability to sweat was also a major factor in our ability to expand out of Africa. Pretty much every other animal has to stop running in order to cool down (eg by panting or wallowing), however humans can continue cooling and regenerating energy while running. This gives us great stamina, so often we can catch up to prey even if they’re faster than us.
We are a unique combination of being biologically adapted to manipulate our environment, evolved to possess adequate intelligence to achieve self-awareness and language, and cultural inheritance through our development of history and communication techniques that allow us to pass on information.
The evolutionary jackpot that human beings struck that no other species has yet is *computational universality*.
Other intelligent species have specialized brains that can handle specific types of problem solving well. Human beings are the only species to be able to externalize our thinking through a series of tricks we have that others don’t which allow us to act as *Turing complete* systems.
A system that is *Turing complete* is capable of computing (solving) anything that is computable as opposed to just solving very specific types of problems. In other words, it is a universal problem solver.
What makes a system Turing complete? In language, a system is Turing-complete if it has conditional branching (concepts like “if” and “then”) and the ability to store data in an arbitrarily large and flexible amount of memory. Once a system has that, it probable that it can solve any kind of problem that can be solved.
What makes human’s Turing complete? Sure we have conditional language but we don’t have arbitrarily large memories:
*writing*
The ability to write things down — or more precisely, the ability to tokenize concepts into language that can be captured and represented outside of our heads — externalizes part of our our brains the way fire externalized part of our our digestion. With that change, we became universal problem solvers.
We had the capacity for this kind of externalized universal thought for hundreds of thousands of years before societies cracked it and we saw an intelligence explosion. You can trace the handful of conceptual inventions that enabled humans to explosively outcompete other similar species.
One theory I have read is that our vocal apparatus and the ability to speak complicated language had a large part of why.
Fire. Specifically the skill to keep one going.
All animals like cooked food. Many animals will dig around for the stuff in the remains of a wildfire. But some early hominid figured out the trick of keeping a fire going, controlling it, and cooking food on purpose.
Fire was just the start of externalizing digestion. It allowed for smaller digestive tracts and bigger brains, and bigger brains were needed to fully reap the benefits. Bigger brains to get better at controlling fire. Bigger brains to get better at managing all the new resources made available. Bigger brains to deal with the social consequences of rapid population growth.
Here’s the 5-yr-old version: Our brains are way more advanced than other animals, even chimps (who have the closest brain to ours). Since we can learn way faster, make complicated decisions and plans, and have conscious thoughts (we know who we are, we can differentiate bw others, we reflect on our decisions, we have a moral compass, we make decisions depending on our changing environment and learn from those decisions), we were able to start and expand our communities. We built tech, started a barter system (trading items) with people all over the world, and created towns/villages/cities/countries with governments. Since we can have conscious thoughts and have a moral compass, we also have bigger desires than just having babies/eggs and finding food (like many other animals). We want to have fun, we want to feel like we are helping society, we want happy relationships, etc. All of this helped us advance over time from small city states to big countries that have governments, armies, trading partners, etc.
The ability to record, store, and retrieve information outside of learned behavior is huge.
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