We tend to understand the brain by metaphor, comparing it against the most sophisticated machine we can think of. The brain as a computer, the brain as a difference engine, the brain as a steam engine, etc. These metaphors start to break down when we really think about what the brain is “for”.
The view we favor is that inference, and cognition more generally, are achieved by a coalition of relatively autonomous modules that have evolved in the species and that develop in individuals so as to solve problems and exploit opportunities as they appear. Just as guerrilla warfare or sailing, cognition is opportunistic.
Ultimately, the brain evolved as one of the mechanisms in the human toolkit for reproductive fitness. It’s wasn’t design to be a strict “computer”, or be “logical”, or be a “machine” in the sense that we normally understand it.
But the brain is an agglomeration of cells, not an engineered system. It evolved to maximize survival in a complex world. To achieve that aim efficiently, the brain mixes functions in ways that can seem like something’s gone wrong, but it does have a good reason. The brain mixes tongue and hand movements with sounds and emotion because it encodes experiences and executes complex movements in a holistic way — not as discrete entities strung together like lines of computer code, but as pieces of a larger conceptual purpose and context.
Any evolved mechanism is adapted to the environmental conditions in which it has evolved and may malfunction or produce nonfunctional effects in different conditions. Modern-day life is very different to the environment our brain evolved for.
For the brain, adaptions take the form of “shortcuts” because the brain is a relentless optimiser.Heuristics and biases (if they even exist at all) are evolutionarily sensible but can lead to what seems like “illogical” thinking, especially given the context shift between modern-day life and that faced by pre-modern humans.
Sometimes human behaviour that seems nonsensical is really non-sensical – it only appears nonsensical because we are judging people’s motivations, aims and intentions the wrong way. And sometimes behaviour is non-sensical because evolution is just smarter than we are.
Further Reading
- Book – The Idea of the Brain by Matthew Cobb
- Book – The Elephant in the Brain by Kevin Simler and Robin Hanson
- Book – Naming the Mind by Kurt Danziger
- Book – The Enigma of Reason by Dan Sperber and Hugo Mercier
- Article – We don’t have a hundred biases, we have the wrong model by Jason Collins
- Article – Against Automaticity by Carcinisation