Evolution and Human Behavior  – a special presentation for Ms. Naclerio’s class

12/5/2011

By Glenn Geher (Megan’s dad – and Director of SUNY New Paltz’s Evolutionary Studies Program)

• How can understanding human evolutionary origins help us understand how people think and behave?
• “Modern humans possess a Stoneage mind in a modern world”
• The Environment of Evolutionary Adaptedness (EEA) – ancestral conditions that characterized what the world was like when our ancestors were evolving into humans.
  • African Savanna
  • PRE-AGRICULTURE – for 99% of human evolutionary history, humans were nomads – following the food as opposed to growing it
  • Civilization and Cities DEPEND ON AGRICULTURE!
  • So there were no cities until about 10,000 years ago (after the advent of agriculture)
  • Bands of humans tended to be capped at about 150 (including many kin members)
  • Droughts were common – and with droughts came famine
  • Average human bands would walk up to 20 miles a day – regularly
  • IMPLICATIONS FOR MODERN HUMAN BEHAVIOR
    • FOOD – since famine was common, people evolved to like foods with high sugar and high fat – these food preferences helped people put on needed fat to make it through famine conditions
      • BUT POST-AGRICULTURE, these food preferences are actually unhealthy!
      • Further, these evolved food preferences explain why McDonald’s has sold billions and billions …
• EXERCISE – our human ancestors were not overweight – partly due to famine conditions – and partly due to exercise. They didn’t need to pay $500 a month to join a gym – life was a gym – and the savanna was their treadmill!
• EDUCATION – under ancestral conditions, there were no schools! People learned by observing and interacting with others in their band. And good evidence suggests that the main teachers of kids were kids who were slightly older than themselves – being outside, doing stuff that needed to be done, and interacting in a mixed-age environment was school for our ancestors. No report cards!
• EVOLUTIONARY MISMATCH
  • When the modern conditions of an animal don’t match the animal’s EEA
  • Humans live in contexts that are, in some ways, very different from the EEA
  • This is partly why we have issues such as obesity in societies like ours
  • Making modern societies more like the EEA might be a key to improving human health.