In fact, their bodies are possibly so optimized for their current hunting strategy that higher intelligence might only trip them up.
It is much more likely that intelligence beyond this point simply costs too much relative to the benefit. Brains use a lot of energy.
How do I put it, so as not to offend anyone… I think this is the right discussion for me to say that although I percieve this comment as positive, this definitely is not one I would wish to allocate my attention to, given the choice. I would have expected such posts to get downvoted. I suggest two separate systems of voting: one for positive fuzzy feelings, one for worthiness of attention. What I hope is that it would mitigate the reluctance to downvote (or to not upvote) stemming from the social nature of humans. I.e. we could continue not discouraging each other while still having a useful conversation.