They’re not terribly sophisticated markings, or obviously social. Even if brain size correlates exactly with capability, doing these at ~40% brain size seems quite plausible.
Brain size in modern humans is also only weakly correlated with intelligence [1]. So they might not even have been stupid due to their smaller brain size.
Sperm whales don't have much of a chance to manipulate their environment, but they have the largest brains on earth [2].
Comments
They’re not terribly sophisticated markings, or obviously social. Even if brain size correlates exactly with capability, doing these at ~40% brain size seems quite plausible.
Brain size in modern humans is also only weakly correlated with intelligence [1]. So they might not even have been stupid due to their smaller brain size.
Sperm whales don't have much of a chance to manipulate their environment, but they have the largest brains on earth [2].
[1] https://www.scientificamerican.com/article/does-brain-size-m....
[2] https://www.amnh.org/exhibitions/extreme-mammals/extreme-bod....