Perceiving the Mind

There's been a ton of research over the last decade or two on what is often called folk psychology or theory of mind (the latter is a bit theoretically loaded). That research concerns who has the ability to reason about other minds -- do young children? autistic children? chimpanzees? dolphins? elephants? -- and what that ability looks like. In most research on the subject, what people consider minds to be, and who they consider to have minds, has largely been taken for granted. While that doesn't mean we haven't learned anything about theory of mind, it does mean we may have missed some interesting aspects of it.

In this week's issue of Science there's a paper presenting research that begins to address those two questions. Gray, Gray, and Wegner1 surveyed 2400 people between the ages of 12 and 75 (with a mean age of 30.44), and asked them to compare several different types of entities that potentially possess minds on several (18) different mind-related capacities. The entities included a frog, a dog, a 7-month old fetus, a chimp, God, a robot (Kismet, pictured above), a person in a permanent vegetative state, a teenager, an adult human, and a dead person. The capacities on which the pairs were compared included the following (descriptions taken from the paper's supplementary materials, which includes a complete list of the entities and capacities, and can be found here):

• Communication: "This survey asks you to judge which character is more capable of
  conveying thoughts or feelings to others."
• Consciousness: "This survey asks you to judge which character is more capable of
  having experiences and being aware of things."
• Desire: "This survey asks you to judge which character is more capable of longing
  or hoping for things."
• Memory: "This survey asks you to judge which character is more capable of
  remembering things."
• Morality: "This survey asks you to judge which character is more capable of telling
  right from wrong and trying to do the right thing.
• Thought: "Thought. This survey asks you to judge which character is more capable of
  thinking."

Other questions asked participants to make personal judgments about things like, "If you could somehow make one only of these characters happy, which one would you choose to make happy?" or "If you were forced to harm one of these characters, which one would it be more painful for you to harm?"

Once all of the data was collected, Gray et al. computed the correlations between each of the capacities, and using factor analysis, determined which capacities were the most strongly related to each other. This analysis produced two dimensions onto which the capacities seemed to map, which Gray et al. called "experience" and "agency." Here is their table (from the supplementary materials page) showing which capacities are associated with the two dimensions:

If the number corresponding to a capacity is in bold font in a column, that means that capacity is associated with that column's dimension. The higher the numbers (which go up to 1.0), the more strongly a capacity is associated with a dimension. So, "Hunger" is the capacity most strongly associated with the experience dimension, and "Self-control" is the capacity most strongly associated with the agency dimension.

After computing these two dimensions, Rich et al. then ranked each of the entities in the survey on each. The results are presented in what could possibly be the cutest graph ever to appear in Science. Here it is (from p. 619):

Awww... wook at the wittle wobot. Aaaanyway, the results of this analysis are really interesting. As you can see, the man and woman, along with "you" (not you, but the survey takers) score really high on both experience and agency. God, on the other hand, scores really, really high on agency, but as low as Kismet (who scored in the middle on agency) on the experience dimension. Perhaps most interesting, to me at least, are the baby, the fetus, and the frog. The baby scored really high on experience (higher, in fact, than the adult humans, including "you"), but really low on agency. This seems to imply that people feel like babies are experiencing everything, but have no will. I'm not exactly sure what to make of that. The fetus scored in the middle, on experience, but only slightly higher than the frog, and its agency score was the same as the frog's (the dead person and the person in a permanent vegetative state actually scored higher on the agency dimension than the fetus, with the dead woman slightly beating out the guy in a PVS). It would be interesting to look at whether individual differences in people's ratings of fetuses on the agency dimension correspond to opinions on issues like abortion and embryonic stem cell research.

Finally, Rich et al. correlated the personal judgments (e.g., "Which would you choose to make happy") with the two dimensions. They found that the extent to which people "valued" the entities was associated with the amount of agency and experience they attributed to them. Thus, the least valued entities were low on both experience and agency, and the most valued entities were high on both. Interestingly, they also note that "deserving punishment" (one of the personal judgments) was more associated with agency than experience, while avoiding harm was more associated with experience. Of this pattern, Rich et al. write:

The dimensions [agency and experience] thus relate to Aristotle's classical distinction between moral agents (whose actions can be morally right or wrong) and moral patients (who can have moral right or wrong done tothem). Agency is linked to moral agency and hence to responsibility, whereas Experience is linked to moral patiency and hence to rights and privileges.

So those are the results. I hope that further, more controlled work will be done to flesh out the structure of these dimensions, and possibly discover others, because looking at this data, I can't help but think that there could be a wealth of future directions for research based on it. For example, how do theory of mind deficits (in autism, e.g.) relate to these two dimensions? Do autistic children have more trouble with agency or with experience? What about nonhuman animals (chimps, dolphins, etc.?). And how do these dimensions correspond to our behavior? How do they affect moral judgments, for example? Are there important individual differences in people's perceptions on these two dimensions? Do vegetarians perceive animals as having more agency? Do people who are anti-choice perceive fetuses as being closer to infants, or even to adult humans, on the two dimensions? Honestly, I can't wait to see what comes out of this research, and I bet that once these dimensions are more thoroughly studied, the implications for other areas of research will be profound.

¹Gray, H., Gray, K., & Wegner, D. M. (2007). Dimensions of mind perception. , 315, 619.