Barbara J. King

Friday Animal Blog

Apes’ pointing

February 11, 2011

Last week, a book chapter published in 2009 migrated to the top of my stack and stopped me cold in my bipedal tracks. Brilliant isn’t a word I throw around lightly but I think it applies in this case.

The chapter, written by David A. Leavens, Timothy P. Racine, and William D. Hopkins and published in the volume The Prehistory of Language edited by R. Botha and C. Knight, is called “The ontogeny and phylogeny of non-verbal deixis.” Non-verbal deixis, or NVD, is the ability for an individual to direct someone else’s attention to a specific location, object, or event. So—who knew?—when I grab my husband and fling a longing hand out towards the chocolate brownies at the bakery counter, I’m engaging in an act of NVD.

Leavens, Racine, and Hopkins explore whether apes can engage in NVD, in particular, pointing. As recently as 2007, psychologist Michael Tomasello claimed that no apes point to share information in a social context. Leavens et al. easily refute this notion via their literature review, even while acknowledging that much ape pointing occurs in interaction with humans.

Wild apes point rarely. Leavens et al. say that it’s unlikely for a wild ape to be dependent on another ape’s directing his attention to some object out of the reach of both. Initially, I thought to quibble here—wouldn’t it be helpful for apes to compel each other’s attention towards predators or moody alpha males?

I’ll return to wild apes in a moment. Regarding captive apes, the typical approach is to suggest that they point only to request some object, not to change their partners’ mental states—as would happen if they intended to inform their companions about predators or ramped-up males. On this view, an ape who pointed to a fig (the ape equivalent of a brownie) would be trying to obtain the fig; by contrast with my Homo sapiens “brownie point,” I could equally well be hinting to my husband that I’d love for him to make brownies that night for dessert.

Psychologists routinely conclude that children only a year old can-- unlike apes--intentionally bring about some sort of mental shift in another person via their acts of pointing. In scientific lingo, then, humans – even little kids-- are mentalists, whereas apes are behaviorists.

It’s this species divide that Leavens et al. so effectively challenge. The notion that small children intend with their acts of NVD to alter someone else’s mental state emerges from a very particular view of cognition—one that situates mental acts (such as representing and intending meaning) entirely within an individual’s head. That’s not, the authors say, the way things really work: “An act of pointing,” for example, “means what it means by virtue of the fact that it is used in some particular interactional situation to do some specific work.” Depending on “the people present, contingencies between the behaviors, the specific physical context, and so on,” a child’s point may mean two different things at two different times. On this view, which I share, cognition is distributed. Not confined to any single mind, it emerges in real-time as social partners interact and create meaning together.

And here is a way out of a dangerous trap. If we attribute the meaning of human pointing to individual psychological states in the head—but then deny these states to apes—that’s a double standard. Recognizing instead that events surrounding a point (by a child or ape) shape its meaning, we see that emergence of pointing depends on developmental (distributed) contexts.

Now we’re ready for the hard-hitting final piece of the chapter: Their developmental histories stack the deck against captive apes, and as a result, researchers as yet have no realistic sense of apes’ NVD behavior.

Sadly, some apes were brought to captivity after witnessing atrocities committed against their mothers in the wild. “No researcher,” remark Leavens et al., “would study the communicative behavior of a group of human children who had experienced this kind of prolonged trauma and then attempt to generalize from that sample to the rest of the human species.” Even young apes born and raised in captivity can’t fairly be compared to children living at home with their parents. After all, these ape youngsters’ mothers lack any control over their lives. “Only human children of slaves or prisoners would be a proper comparison group for these apes,” Leavens et al. assert.

Dave Leavens amplifed his thinking on wild apes’ pointing in an email message. Wild apes, he believes, “are virtually never dependent upon another ape to act on the environment for them.” Compared to humans, they locomote independently from a younger age, and thus obtain on their own what they need from the environment. When their access to a resource is somehow blocked, and it becomes meaningful for wild apes to point—they do.

Comments

  1. February 11, 2011 11:14 AM EST
    Sounds fascinating! Seems like gaze-following would be interesting to pursue here as well. I am trying to remember the sources, but I feel like I've read about examples of apes using their gaze as a deliberate pointer. I remember an anecdote in De Waal about an ape starting at him, staring at something over his shoulder - staring at him, staring at something over his shoulder....
    - Jen
  2. February 11, 2011 11:57 AM EST
    Yes, Jen, I remember de Waal had a brief article about variability in how ape NVD might be expressed, including via gaze; either Roger or Debi Fouts once mentioned in print that chimpanzees may also point with their chins. Surely these behaviors would be equally subject to being acted upon by social partners, in the same distributed way--once the acts are "out there," meaning may be constructed around them. Also, don't some human populations-- or rather some individuals within some populations-- point with parts of the body other than the hand?
    - Barbara J. King
  3. February 11, 2011 1:52 PM EST
    I am familiar with the 2009 article and others, but what I so admire here, Barbara, is your writing about NVD in such a way that it is summarized so entertainingly and clearly. No wonder you are such a great teacher! I would refer anyone who is a little unclear on the concept to READ THE BLOG.
    - Joanne Tanner
  4. February 11, 2011 2:03 PM EST
    I appreciate these words, Joanne. I learn so much from writing these blogs, because doing so forces me to turn things over and think in new ways. Of course in this case it was a plus that Dave Leavens is so generous with his time, modelling distributed cognition in scholarship!
    - Barbara J. King
  5. February 11, 2011 5:29 PM EST
    I agree with Joanne that this is a great explanation of NVD, and some of the problems of comparing ape and human cognition. Why do we think pointing is something so indicative of cognition? I've also read that pointing with the finger is not a human universal. So it seems to be another thing that enculturated apes do, but wild ones do not.

    Also, I think dogs often succeed at pointing tasks. I didn't have time to read it closely, but this is an interesting looking review of pointing across species.
    - Laurie (@DrYapyapi on Twitter)
  6. February 11, 2011 5:30 PM EST
    Oops! Forgot the link to the article!
    http://familydogproject.elte.hu/Pdf/publikaciok/2006/miklosiS2006.pdf
    - Laurie (@DrYapyapi on Twitter)
  7. February 11, 2011 7:11 PM EST
    Laurie, it's great to see your comments here, many thanks. Adam Miklosi's comparative cognition work is quite good. I've read that article, but will have to refresh on the details. Meanwhile, the interesting thing about Leavens et al. is that they think wild apes DO point -- not often, maybe, but only because their environment and aspects of their development combine to bring about a situation in which it's rarely necessary. Does that part of their argument work for you?
    - Barbara J. King
  8. February 11, 2011 7:24 PM EST
    Ah, yes, that does work for me. It reminds me of all the work on tool-use. So many more primates use tools in captivity then in the wild, but do they really NEED to use them in the wild? In a lot of ways all this comparative cognition stuff is like comparing apples and oranges.

    - Laurie (@DrYapyapi on Twitter)
  9. February 22, 2011 11:38 AM EST
    Perhaps pointing did not become a significant toll in apes' communicative repertoire because, as arboreal species, they couldn't let go of the tree to point?
    - Melanie
  10. February 22, 2011 7:08 PM EST
    Melanie, I'm skeptical of arboreality as an explanation because the heavily arboreal orangutans in Sumatra readily use tools, manually and with dexterity -- and of course the arboreal/terrestrial chimpanzees do so in populations right across Africa. If the apes' lifestyle doesn't preclude manual tool use, it shouldn't preclude pointing. And all the great apes freely gesture manually in the wild!
    - Barbara J. King

Selected Works

Nonfiction
Why are animals so irresistible to us? Why do we live with and care so deeply about them? From the famous "art caves" of ice-age Europe, to the ancient villages where animals were first domesticated, to stories of apes, whales, dogs, and cats doing fascinating things today, King weaves together a scenario about the animal-human bond that encompasses our past, present and future.
Can scientists discover a prehistory of religion just as they have traced the evolution of technology, language, and art? What does compassion in chimpanzees, or burial patterns in our human ancestors and Neanderthals, tell us about the origins of religion? In Evolving God, named a Top Ten Religion Book for 2007 by the American Library Association, Barbara King explores these questions.
How do chimpanzees, bonobos, and gorillas-- the African apes -- communicate using body postures and gestures? Using her many years of experience studying these apes, Barbara King answers this question in a book that offers a new perspective on the evolution of language.