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BEYOND REWARD AND PUNISHMENT
David Deutsch

David Deutsch is a quantum physicist and a member of the Centre for Quantum
Computation at the Clarendon Laboratory, Oxford University. He is the author of The
Fabric of Reality and The Beginning of Infinity.

First Murderer:
We are men, my liege.
Macbeth:
Ay, in the catalogue ye go for men,
As hounds and greyhounds, mongrels, spaniels, curs,
Shoughs, water-rugs, and demi-wolves are clept
All by the name of dogs.
William Shakespeare – Macbeth

For most of our species’ history, our ancestors were barely people. This was not due to
any inadequacy in their brains. On the contrary, even before the emergence of our
anatomically modern human sub-species, they were making things like clothes and
campfires, using knowledge that was not in their genes. It was created in their brains by
thinking, and preserved by individuals in each generation imitating their elders.
Moreover, this must have been knowledge in the sense of understanding, because it is
impossible to imitate novel complex behaviors like those without understanding what the
component behaviors are for.26
Such knowledgeable imitation depends on successfully guessing explanations,
whether verbal or not, of what the other person is trying to achieve and how each of his
actions contributes to that—for instance, when he cuts a groove in some wood, gathers
dry kindling to put in it, and so on.
The complex cultural knowledge that this form of imitation permitted must have
been extraordinarily useful. It drove rapid evolution of anatomical changes, such as
increased memory capacity and more gracile (less robust) skeletons, appropriate to an
ever more technology-dependent lifestyle. No nonhuman ape today has this ability to
imitate novel complex behaviors. Nor does any present-day artificial intelligence. But
our pre-sapiens ancestors did.
Any ability based on guessing must include means of correcting one’s guesses,
since most guesses will be wrong at first. (There are always many more ways of being
wrong than right.) Bayesian updating is inadequate, because it cannot generate novel
guesses about the purpose of an action, only fine-tune—or, at best, choose among—
existing ones. Creativity is needed. As the philosopher Karl Popper explained, creative
criticism, interleaved with creative conjecture, is how humans learn one another’s
behaviors, including language, and extract meaning from one another’s utterances.27

26 “Aping” (imitating certain behaviors without understanding) uses inborn hacks such as the mirror-neuron
system. But behaviors imitated that way are drastically limited in complexity. See Richard Byrne,
“Imitation as Behaviour Parsing,” Phil. Trans. R. Soc., B 358:1431, 529-36 (2003).
27 Karl Popper, Conjectures and Refutations (1963).

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