Babies’ number sense is logarithmic

According to Lisa Pollack in the Financial Times of 23 December, presumably drawing on some neuro-science research:

Babies think in logs. In logarithmic scales, that is. This means that newborns are able to notice when an image of eight ducks on a screen switches to an image of 16 ducks. We notice they notice because when the switch happens to the larger flock, there’s an observable spike in activity in the parietal lobe of a baby’s brain.

This isn’t just about babies noticing that something has changed — a switch on the screen between eight ducks and eight trucks lights up a different region of the brain. That babies can clock a large percentage increase in quantity, such as 100 per cent in the case of the ducks, but not a small one (say, between eight and nine ducks) is what defines their innate sense of numbers as logarithmic rather than linear. In contrast, integers, and the linear scale we place them on, is something that we have to learn by rote when our parents teach us how to count. It’s a cultural construct.

This is useful for our S2 “How Random Can You Get?” investigation.