The Startup Problem

The Start-Up Problem #

We need cumulative culture to be successful. When/how did this accumulate in the first place?

• “Crossing the rubicon”: once stealing knowledge from others was more efficient than learning it yourself, there was no turning back

2 pathways: #

1. Know-how (mechanical)
2. Sociality (brain cost/ability)

Terrestrial Primates: #

• Since humans don’t use arms for swinging on trees, they are free to use for innovating new behavior.
• Less safety from predators → incentive to increase group size, become diurnal

Know-How Pathway #

Terrestrial → Greater danger → Larger social groups → More opportunities to learn → More knowledge of tool-making → More social learning

Larger social groups → Pair bonding strategies → Expanded kin → Childcare → Reduced development cost → More social learning (Care pathway)

Tinbergen Analysis: #

• Phylogeny: apes w/ hands, color vision, terrestrial living
• Function: needed large groups to survive
• Mechanism: increased social information + learning opportunities
  • Feedback loop: increasingly large brain ↔ more learning
  • Ability to survive rapidly changing environments

Why Collective Brain? #

• Thinking is expensive. Larger brain = larger cost
• Reducing individual load ⇒ ability to develop even larger brain
• Humans were physically disadvantaged, needed to specialize
  • Invented mechanisms to efficiently force-thrust. No longer needed to support

large teeth, etc.

• endurance hunting: chasing prey for up to 8 hours to take down animals who sprint / not adapted for long periods of movement
  • running in heat, accurate tracking
  • lost hair, increased sweating, olfactory glands for social information, stabilized head, springy feet, large butt

Cooking #

How the body processes food!

• Mechanical (chewing)
• Chemical (stomach, small intestine, colon — break down, extract, store)
• Problem: humans have a small digestive system. can’t process much food. Most suited for carnivores (ill equipped to break down plants)

Humans not adapted for raw food: control of fire to cook food

• possibly 1.5 mya: presence of cook fire (learned from wildfires)
• adap

Human: