Raised cortisol levels have been found in children separated from family for thirty or more hours a week, especially those in substandard care.
But what was the paper doing in a biology journal anyway? Maybe the underlying assumptions should be unpacked.
Two things: If the significant changes happen to humans between birth and seven years of age, it is not q theory of evolution at all, but of intellectual and cultural development. Also, Tomasello seems not be following the party line that apes are just like us but we refuse to recognize the fact. That’s borderline heresy.
Maybe greater social intelligence is the outcome of a much higher order of underlying intelligence in humans?