My guess is that abstract ideas is an outgrowth of language and also necessary for the development of the complex societies the article is positing. I would als

My guess is that abstract ideas is an outgrowth of language and also necessary for the development of the complex societies the article is positing. I would also be careful not to conflate complex language (for example, dialects in whales) with the development of complex abstract ideas (for example, mathematics). It seems to me the latter is necessary for the complexity discussed, but unclear if the extent to which it exists in other species. But I agree, hopefully we can learn more someday on the way they are both similar and dissimilar to human cognition. (I should add that there are some like Stephen Meyer who think certain abstract cognition is more magical and unable to come from basic evolution, but this has a theistic bent)