I’ve been looking for this.
One Google search away.
Along with this hint at r-selection.
“…Any new set of conditions which render a species’ food and safety very easily obtained, seems to lead to degeneration….”
Excuse me while I hide in shame.
My money’s on disinhibition from hypofrontality.
The loss of cellular material in the frontal lobe would scale us back to an earlier stage in evolution.