Many researchers in the behavioral sciences are interested in the taxonomic distribution of which nonhuman animals (animals) have a Theory of Mind (ToM). Basically, ToM "is the ability to attribute mental states -- beliefs, intents, desires, pretending, knowledge, etc. -- to oneself and others and to understand that others have beliefs, desires, intentions, and perspectives that are different from one's own." Many people think that if any nonhumans have a ToM it is the great apes. The purpose of this brief essay is to call attention to the possibility of non-primates having a ToM by focusing on social play behavior. A narrow taxonomic focus on great apes -- ape exceptionalism -- makes it seem that the great apes are exceptional among nonhumans. There is no reason to assume this given the paucity of data on other species. 

A recent essay by Rachel Feldman in the Washington Post called "Can all great apes ‘read minds’ like humans do?" made me reflect on the taxonomic distribution of ToM among nonhumans. In this piece, Ms. Feldman writes about a new paper by Christopher Krupenye and his colleagues published in the prestigious journal Science called "Great apes anticipate that other individuals will act according to false beliefs." This essay is not available online. A brief description and abstract read as follows:

Apes understand false beliefs

We humans tend to believe that our cognitive skills are unique, not only in degree, but also in kind. The more closely we look at other species, however, the clearer it becomes that the difference is one of degree. Krupenye et al. show that three different species of apes are able to anticipate that others may have mistaken beliefs about a situation (see the Perspective by [Frans] de Waal). The apes appear to understand that individuals have different perceptions about the world, thus overturning the human-only paradigm of the theory of mind.


Humans operate with a “theory of mind” with which they are able to understand that others’ actions are driven not by reality but by beliefs about reality, even when those beliefs are false. Although great apes share with humans many social-cognitive skills, they have repeatedly failed experimental tests of such false-belief understanding. We use an anticipatory looking test (originally developed for human infants) to show that three species of great apes reliably look in anticipation of an agent acting on a location where he falsely believes an object to be, even though the apes themselves know that the object is no longer there. Our results suggest that great apes also operate, at least on an implicit level, with an understanding of false beliefs.

In the above piece Ms. Feldman refers to another of her essays called "Ravens know when they’re being watched." So, at least these birds show the possibility of a ToM. But what about other animals?

Social play in animals and ToM: Fine-tuning on the run

Now that discussions of nonhuman ToM are back in the news, I'd like to revisit the possibility that when animals engage in social play there is every indication that to be able to play fairly and cooperatively they too display a ToM (for more on this please see "How and Why Dogs Play Revisited: Who’s Confused?"). Let's consider dog-dog play between Harry and Mary.

Marc Bekoff
Source: Marc Bekoff

There are ample data that show that there is a good deal of rapid thinking, feeling, and fine-tuning on the run when animals play. So, for example, let's consider the possibility that Harry has thoughts and feelings based on what he thinks and feels Mary is likely to do during an on-going interaction (and vice versa). These sorts of interactions make it clear that play is also a good place to observe and to study ToM because Harry and Mary need to pay very close attention to what each has done and is doing, and how that will influence what she or he is likely to do in the future (for further discussion please see Alexandra Horowitz's essay called "Attention to attention in domestic dog (Canis familiaris) dyadic play"). There is a good deal of mind-reading going on here as Harry and Mary make careful and rapid assessments and predictions of what their play partner is likely to do. 

Ample data for a number of different species show there are predictable rules of play that cross species lines, namely, ask first, be honest, follow the rules, and admit when you’re wrong. This is why play is so exciting to engage in and also so much fun to watch and to study. And, this is also why play among young and old dogs, for example, only rarely escalates into injurious aggression. Indeed, Shyan, Fortune, and King (2003) reported that fewer than 0.5% of play fights in dogs developed into conflict, and only half of these were clearly aggressive encounters. Their data agree with our own observations on wild coyotes and other free-running dogs at play.

Ape exceptionalism is too narrow a view, and I hope researchers will begin to look for ToM in a wide range of species in different venues in which it is expected that ToM would evolve. Comparative data would be illuminating to ponder and might expand the taxonomic range of ToM to a wide variety of nonhuman animals. 

Please stay tuned for more on the fascinating cognitive and emotional lives of other animals. This is a "hot" area of research, and almost daily we learn not only something new about how they live in a wide variety of social environments, some of which change rapidly over time, but also about the cognitive and emotional capacities/adaptations that allow them to do so. 

Marc Bekoff’s latest books are Jasper’s Story: Saving Moon Bears (with Jill Robinson), Ignoring Nature No More: The Case for Compassionate Conservation, Why Dogs Hump and Bees Get Depressed: The Fascinating Science of Animal Intelligence, Emotions, Friendship, and Conservation, Rewilding Our Hearts: Building Pathways of Compassion and Coexistence, and The Jane Effect: Celebrating Jane Goodall (edited with Dale Peterson). The Animals’ Agenda: Freedom, Compassion, and Coexistence in the Human Age (with Jessica Pierce) will be published in early 2017.

You are reading

Animal Emotions

Did Szenja the Polar Bear Die of a Broken Heart?

It's the best explanation of the sudden death of a polar bear at SeaWorld.

Animal Envy, by Ralph Nader: A Review

The book's core message is that nonhumans and humans need each other

Mice Aren't Furry Little People: Sloppy Science Fails Humans

NPR News: Animal models for drugs don't work well on humans