The reason this corvid study is different from intuitively knowing that 10-10=no berries is where this 0/empty set is represented on the numberline.
Considering 0 as a number vs the empty set are two different concepts. It’s the difference between having a bank account with $0, vs having no bank account. They don’t close your account when you have $0, so it’s still an amount of money.
Crows considering 0 on the numberline, and differently from the empty set shows they have a more abstract concept of numbers than we thought.
Idk who authored this study, seems like a very specific kind of person who is both into number theory and neural pathways of birds to design.
Or Anthropology. Right now, we have realized that New Caledonian crows have entered an equivalent to the early stone age in humans. Therefore, we can gain a lot of insight both about the nature of technological progression and of the very nature of intelligence (and the differences between mammalian and avian intelligence) by doing these studies.
