On HumansOctober 18, 202301:10:1448.23 MB

28 | A Natural History of Equality ~ Sarah Brosnan

“Why do we care about equality? Is it an invention of the European Enlightenment? Or is it something rooted in human nature?”

These questions launched episode 15 with philosopher Elizabeth Anderson. Titled “A Deep History of Equality”, our conversation ranged from Pleistocene hunter-gatherers to Chinese communism. 

Today’s episode continues the quest. But this time, we go further and contrast humans to other apes and monkeys. 

My guest is the primatologist Sarah Brosnan. Her research is famous for a wildly popular video clip of a monkey who, frustrated by unequal treatment, throws a cucumber at the experimenter. You might have seen the video. Do watch it if you have not. It's only 58 seconds long.


I saw this clip years ago. It resonated with something in me. But what exactly? Why should we care about monkeys throwing cucumbers? Are the critics right who say that this has nothing to do with human values?

It was an honour to discuss this with Prof Brosnan herself. We start by exploring cucumber throwing (i.e. "inequity aversion") in a variety of species. We then move to topics such as:

  1. Can monkeys learn more egalitarian social norms?
  2. How do monkeys (or chimpanzees) react to unfairness when they are the ones benefitting?
  3. Answering the critics: is this really about social equality?
  4. Does fairness improve cooperation?
  5. Are there property rights in the primate world?
  6. Is there still something special about humans?

As always, we end with my guest's reflections on human nature.

I hope you enjoy the conversation!


Do you prefer reading to listening? Or would you like to revisit the argument’s highlights? You can now get breakdowns of this and other episodes directly to your email. Subscribe via the On Humans SubStack or read on the web.

The breakdown of this conversation is available now!


Malini Suchak / Frans de Waal / Julia Neiworth / Erin Musto / Friederike Range / Jason Davies / Michael Tomasello / Felix Waerneken 


For links to mentioned papers and talks, see https://onhumans.substack.com/p/links-for-episode-28.