Kurt Gray, Liane Young, and Adam Waytz argue [pdf] that our belief that other people have minds is at the heart of our morality:
In 1945, Pablo Picasso distilled the essence of a bull. In a series of fifteen drawings, he took the full complexity of the animal and reduced it to a dozen lines (Figure 1). Although this final sketch does not capture the idiosyncrasies of every particular animal, it remains a compelling representation – a template – of the broader concept. If we attempted to distill the essence of morality, what would result? The full set of ―immoral acts is undeniably complex, and includes murder, cheating, theft, incest, disobedience, and disrespect, to name only a few. Despite this diversity, we suggest that the human mind acts as Picasso did, abstracting out the key elements from various moral transgressions to create a cognitive template. These key elements are intention and pain (i.e., intentional harm) and that the essence of moral judgment is the perception of two complementary minds – a dyad of an intentional moral agent and an suffering moral patient.
(Image via Gray at Experimental Philosophy.)