If a creature can only add, say, integers less than nine, do they really grasp what addition is? Whatever faults generalized conceptual holism might have, isn’t it still pretty plausible for the concept of addition?
Tad Zawidzki emailed the following link to a video of a mathematical monkey (Thanks, Tad!):
The following link describes the relevant research:
Not unrelated is Tanasije Gjorgoski’s recent post on whether babies intuit that 1+1=2: