A look at the seven emotional systems of the brain by the researcher who discovered …
As far as we know right now, primal emotional systems are made up of neuroanatomies and neurochemistries that are remarkably similar across all mammalian species. This suggests that these systems evolved a very long time ago and that at a basic emotional and motivational level, all mammals are more similar than they are different. Deep in the ancient affective recesses of our brains, we remain evolutionarily kin. This has long been evident in our body structures and biochemistries.
— Archaeology of Mind by Jaak Panksepp, Lucy Biven (Page 4)