Peterson is well aware of the differences in brain chemistry between lobsters and humans, but this difference is not incompatible with the claim that hierarchie

Peterson is well aware of the differences in brain chemistry between lobsters and humans, but this difference is not incompatible with the claim that hierarchies have existed well before human societies, and that serotonin levels correspond to the position in that hierarchy for both lobsters and humans. If you can find a biologist to refute this, then your argument would have merit.