[Wanderer99]

Babies cannot be “mean spirited”. They are simply selfish/self-centered.

That’s not exactly a shock. They lack the cognitive development and training for super-ego behavior.

[doberville]

'Mean spirited', I believe refers a feeling state: controlled by the limbic center, the earlier, less developed reptilian part of the brain than the cortex, where thinking occurs.

Cognitive development involve the neocortex.

Not sure that is applicable here.