Sigmoids may look like exponential growth at first, until they saturate. Early growth alone cannot distinguish between them.

Intelligence must be sigmoid of course, but it may not saturate until well past human intelligence.

Intelligence might be more like an optimization problem, fitting inputs to optimal outputs. Sometimes reality is simply too chaotic to model precisely so there is a limit to how good that optimization can be.

It would be like distance to the top of a mountain. Even if someone is 10x closer, they could still only be within arms reach.

If it's exponential growth. It may just as well be some slow growth and continue to be so.

On the other hand: Perception of change might not be linear but logarithmic.

(= it might take an order of magnitude of improvements to be perceived as a substantial upgrade)

So the perceived rate of change might be linear.

It's definitely true for some things such as wealth:

- $2000 is a lot of you have $1000.

- It's a substantial improvement of you have $10000.

- It's not a lot you have $1m

- It does not matter if you have $1b

$2000 is not substantial over $1b on the linear scale

2k is the same on the linear scale no matter where you are. that's what the linear scale is about.

you're already interpreting this on the log scale