Some neuroscientists say they have shown hardwiring in studies of crows and macaques but others say no, these life forms differ too much:
Testing the hardwiring thesis, Andreas Nieder reported spikes of activity in the prefrontal cortex of macaques reacting to three objects of interest, relative to two or four. Later, he and colleagues found that crows, who lack a neocortex, The researchers later recorded evidence of neurons in the avian endbrains of crows that respond to specific numbers of objects from one to five. Crows don’t have a prefrontal cortex so, as Offord notes, they suggested convergent evolution (convergence on a common goal rather than common ancestry) as an explanation. Even so, they say, the quality is probably innate.News, “Are our neurons really wired for numbers?” at Mind Matters News
Harvey notes that at least some activity reported as number-specific may instead be related to attention or other aspects of task performance rather than to numerosity per se, and adds in an email that it’s unlikely that macaques and humans, which diverged more than 20 million years ago and have different brain structures, are using exactly the same neural machinery.”Catherine Offord, “Is Your Brain Wired for Numbers?” at The Scientist (October 1, 2021)
Now, Nieder’s group isn’t saying that numerosity is inherited from a common ancestor. In the case of macaques vs. crows, inheritance from a common ancestor of both would take us a long way back into the history of life. That is why the researchers think that the ability is more likely a result of convergent evolution. They are suggesting that it is an “innate” quality that develops differently in different life forms that are are all seeking to solve the same problem — should they take risks and expend energy to acquire this food resource or that one?
The reality is that we don’t have the information we need to decide as yet whether numerosity is a hardwired trait or simply an outcome of general awareness.
But it’s interesting how often convergent evolution is invoked these days.
You may also wish to read: Evolution appears to converge on goals—but in Darwinian terms, is that possible?
Here are some fun recent items on animals and number sense:
Pigeons can solve the Monty Hall problem. But can you? The dilemma pits human folk intuition against actual probability theory, with surprising results. In one 2010 study, pigeons outperformed humans in the three-doors test but in a second 2012 study, they only beat preschoolers, not college kids.
Is our “number sense” biology, culture — or something else? It’s a surprisingly controversial question with a — perhaps unsettling — answer. Mathematics supports a dualist view of the universe. Both concrete and abstract, depending. Both the Chimp Chocolate Stakes and Chaitin’s Unknowable Number.
Why animals can count but can’t do math. A numerical cognition researcher outlines the differences between recognizing numbers and doing math. Psychologist Silke Goebel says that the cardinality principle — the highest number in a series sums the numbers, takes children some time to learn.