ADAM WAYTZ: What I like about studying humanization and dehumanization is that we now have a variety of methods at our disposal. And neuroscience is often not the perfect method to study a lot of things, but it offers a great insight to humanization and dehumanization because we now know that there is a prescribed set of regions that tends to come online, or be preferentially active, when people are thinking about people -- thinking about people versus objects, playing a game with a person versus a machine, thinking about others' mental states -- their thoughts, their preferences, their desires, rather than thinking about physical aspects of themselves. And we know that these brain regions are responsive to a lot of different stimuli, but they also seem preferentially active toward human beings, or cues to human beings. So that signal of these brain regions that we could call the mentalizing network, or some people call it the social brain network, operates as a nice measure of: How much are you deeply engaging with another person as fully human, or are you engaging with another person's mind? And what the studies have shown is that not all groups are perceived to be equally human.

So to the extent that you are less engaged with another person as a human being -- so this could be viewing, in the fMRI scanner, someone who is homeless, or someone who you believe is addicted to drugs, oftentimes the signal in these brain regions is lower. Or at times, if you're viewing an outgroup member, someone of a different ethnicity or a different geopolitical background from you, oftentimes you get reduction in these brain regions as well. And so the neuroscience offers us a way to nicely gauge the extent to which we're really perceiving another person as fully human, or whether we're turning our humanization down a notch and seeing them as somewhat less than human.

One of the reasons that humans seem to be psychologically important comes from the mere power of human touch. So there are several studies that suggests that human touch has an almost, say, magical power. So there are studies showing that people experiencing pain, if they hold the hand of a loved one, they actually experienced the sting of that pain less aversively. There are studies showing that NBA teams that touch each other more on the court -- more back slapping, more handshaking -- perform more cooperatively on the court and perform better. Something about touch signals cooperative intent. And then there are studies showing that people value objects and goods that are handmade more than objects and goods that they believe are machine-made. And the reason why they value handmade goods to a greater extent, even when it's the exact same good, whether it's a scarf or a coffee mug, if you tell people it's handmade, they believe that the good was somehow made with love. So human touch signals cooperation. It signals care. And it also signals authenticity. And so human touch can give a lot of meaning to mundane experiences and objects as well.