What was the tiny difference that made all the difference? What was it that initially set off hominin brains on a path of exponential development, leaving other Great Apes behind?
Several scientists have looked for an answer by studying the differences between how human and other Great Apes’ brains operate today. Michael Tomasello at the Max Planck Institute in Leipzig, Germany is well known in this field. He and his team have pinned the main difference down to one thing: humans have and sustain a great curiosity about others’ thoughts.
What triggered it?
In his now classic movie “2001: A Space Odyssey” Director Stanley Kubrik suggests that it was picking up a bone to use as a weapon. This is in line with the longtime majority view that the trigger was collaboration amongst males for hunting and war.
Susan Blaffer Hrdy has a more plausible theory. In her book “Mothers and Others” she argues that the difference lies in collaboration among females for gathering food and caring for infants. Humans are the only Great Ape where mothers entrust their offspring to others. Although in the animal kingdom about 9% of species are collaborative breeders, among primates the only monkey other than humans to let others hold and feed their young are marmosets and tamarins. No Great Ape mother lets newborns out of their arms until they are able to move by themselves.
The theory is that this simple recipe:
Advanced Great Ape brain + Collaborative Breeding = Super Curious Brain
resulted in a curiosity about other’s minds which made us capable of sophisticated collaboration, language, and ultimately of sending people to the moon. It worked via a couple of simultaneous forces:
- infants becoming and remaining curious about the thoughts in caregivers (“friend or foe?”) and perfecting the skill of eliciting and obtaining nurture from less dedicated matures than their mothers
- females in their prime, freed of being the exclusive carers of infants 24/7 – becoming more innovative and effective in gathering food, providing increased calories for the increasing energetic demands of brains.
- Documentary: World’s Most Genius Ape (one hour) A fabulous documentary about the differences between Great Apes and 2.5 year old children.
- Article – “How Humans Evolved Supersize Brains” Quanta Magazine
- Why are babies so dumb if humans are so smart? (The New Yorker, Sept. 2016)