Friday, February 4, 2011

Touching Death

The following guest post by Eric Michael Johnson is part of the Primate Diaries in Exile blog tour. You can follow other stops on this tour through his RSS feed or follow him on Twitter. If this is your first time visiting The Prancing Papio make sure to browse some of the other posts on the blog. Thanks. - EMJ

I had always been afraid of my grandfather and now I was staring at his pale, lifeless hand inches from my face. But the very same arthritic fingers I had seen him use countless times to push tobacco inside his pipe or the hard candies he loved into his toothless mouth now just looked wrong to me. They were alien and artificial. It was as if a sculptor had taken the man I knew and placed a life-sized replica in his coffin to fool us. I had to touch him. Later I would learn that this impulse wasn’t unique to that curious ten-year-old attending his first funeral.

In fact, no lesser a figure than the famous 17th-century English parliamentarian and diarist Samuel Pepys would be similarly tempted. After attending a public dissection at London’s Barber-Surgeons Hall one evening in 1663 he enticed his host to let him see the body alone, a sailor who had been hanged for robbery. Afterwards, in the flickering candlelight, Pepys wrote in his diary what I might have expressed myself if I’d had the vocabulary. “I did touch the body with my bare hand; it felt cold, but methought it was a very unpleasant sight.”

There is something intensely animal about our relationship with the dead. As an atheist I don’t feel particular reverence or awe at the site of a cadaver. It mostly just creeps me out. But even religious believers, those who should be comfortable with the idea that a dead body retains no trace of the person they once knew, also seem to have trouble letting go of what St. Paul called “confidence in the flesh.” In funerary observances around the world cadavers are regularly touched, kissed, washed, anointed with oils, bedaubed with ceremonial makeup, carted to sacred ground, entombed with their clothes or belongings, and generally treated in death as if their body were going on a different journey than miasmic decay.

However, as is often the case where human universals are concerned, looking to similar behaviors in other animals can be especially instructive. For example, a study that has just been released in the American Journal of Primatology has captured the most complete process to date of what could only be described as mourning behavior in nonhuman primates. Katherine Cronin and colleagues at the Max Planck Institute, Gonzaga University, and the Chimfunshi Wildlife Orphanage Trust in Zambia have documented a case where a chimpanzee mother faced what for most of us would be an unthinkable horror: the death of her child.

Video footage by Cronin et al. 2011.

The infant had been observed behaving sickly ever since birth when, on May 18, 2010, researchers saw the chimpanzee mother, Masya, carrying the dead body of her offspring. Masya continued to carry her lifeless child until the following day when observers were present to record what they saw next. The infant was placed in a clearing while Masya sat a short distance away staring at the motionless form. Researchers recorded over the next hour as the mother approached her offspring 23 times to place her hands on the child. 21 of these contacts were directed toward her offspring’s face or neck. At the end of this display Masya once again picked up her infant and carried her to the center of the social group about 20 meters away. When she laid her infant down the other group members, eight in total, proceeded to gently touch, stroke the dead infants belly, and groom it with straw. After about twenty minutes Masya retrieved the body and walked off. The next day Masya was observed on her own, she had let go of her dead child.

This is not the first time that primates have been observed to pay special attention to a deceased member of their group. In April last year similar behaviors were observed by a chimpanzee mother in Bossou, Guinea who ended up carrying her infant’s body for a total of 27 days. The mother, Jire, regularly groomed and slept next to her infant’s body and showed distress whenever they became separated. In 2000 a chimpanzee mother in the Mahale Mountains of Tanzania carried her infants body for nearly four months and individuals throughout the community were heard making distinctive vocalizations that the researchers had come to associate with fear and agitation. Other cases have been observed in the mountain gorillas of Rwanda, baboons of Ethiopia, macaques in Japan, and ring-tailed lemurs of Madagascar (see the timeline below).

There have also been notable examples of care being taken with the dead in African elephants and bottlenosed dolphins. In the case of the elephants, an ailing matriarch was observed to receive support from unrelated members of her group, behaviors that couldn’t be explained by either Hamilton’s theory of kin selection nor Trivers theory of reciprocal altruism. This concern with her body continued after death. Further study looked at how the group interacted with the bones of their former group mates and confirmed that the famous behaviors observed at elephant graveyards are intentional, individuals focused more intently on these remains than to other features of their environment. According to lead author Iain Douglass-Hamilton, these results challenge existing theories on where altruistic behavior ultimately comes from.

“The conclusion must be that elephants are interested in the sick, dying or dead elephants irrespective of genetic relationship,” he said. “There seems to be a generalized response to elephants in distress, rather than help or interest only being restricted to close kin.”

In a similar way to what primatologist Frans de Waal has documented in chimpanzees, the individuals appear to experience empathy with those who are sick or dead. But does this mean that nonhuman animals have a concept of death? According to Katherine Cronin in the case of the chimpanzee Masya the behaviors are certainly suggestive of this.

“These behaviors would supply tactile and visual information about the current state of the body,” she said. The mother was intently observing her infant, her eyes rarely straying from the body as it lay in the sun. Likewise, as she was touching her baby’s face or neck, could note the absence of breath or lack of blood circulation warming her tiny frame. “Conceivably, this information could be remembered the next time she encountered the same set of cues,” Cronin said. In this way, the implications of death could be learned by chimpanzees.

At the Sanaga-Yong Chimpanzee Rescue Center, chimpanzees look on as Dorothy--a beloved female felled in her late 40s by heart failure--is borne to her burial. Image: National Geographic / Monica Szczupider

Our desire to touch the dead, to adorn them in their Sunday best and wish them a final farewell, is the human process of gathering similar information. It is a way to reconcile our deep familiarity with the body of our loved ones with the realization that what they may once have been is no more. I’m not even certain that we have a concept of death beyond what we can tell from directly comparing what is different between the living and the dead. I certainly didn’t as a ten-year-old child shuffling past my grandfather’s coffin. In my desire to touch his cold hand I may have been fulfilling a need that many animals experience when confronted with their own realization of death. Whether it’s a chimpanzee mother carrying her dead infant on her back, or what the New York Times reported of the woman from Plainfield, New Jersey who “talked to her dead infant as though it was alive” as she rode the crowded rail car home, the effect may be to ease our minds towards acceptance. For regardless of where we started in life, we all end up in the same place. Death is the great unifier and as we reach out to touch the dead, we are ultimately connecting with everyone else who is struggling to let go.


Katherine A. Cronin, Edwin J.C. van Leeuwen, Innocent Chitalu Mulenga, Mark D. Bodamer (2011). "Behavioral response of a chimpanzee mother toward her dead infant," American Journal of Primatology, Article first published online: January 21, 2011. DOI: 10.1002/ajp.20927


Patrick Clarkin said...

Great post, Eric! (And thank you for hosting, Raymond). I wonder what goes through the mind of an ape that encounters a deceased mate, relative, or friend. There seems to be a lot of variation in how long some mothers hold onto the bodies of their deceased infants, which implies a less canalized behavior. Perhaps there is no set instinct in how to deal with such a profound event, and each individual deals with it however they can.

There are related stories out there, such as one in captive chimps in Scotland where the daughter slept near the body of her deceased mother, and Goodall's descriptions of the juvenile Flint who died shortly after his mother passed away. Like us, apes seem capable of severe grief over death.

Eric Michael Johnson said...

Thank you for your comment Patrick. I know very well what you're referring to with Flint's behavior after his elderly mother Flo died. He refused to leave his nest or eat and he eventually died. I first came across this example when I saw the wonderful documentary The People of the Forest. It was heartbreaking to watch.

This was also the documentary that introduced the idea that chimpanzees display behaviors that evoke human conceptions of God. During a thunder storm one alpha male grabbed a large branch and proceeded to make threat displays as one male would to another. He thrashed about to make as much noise as he possibly could to seemingly intimidate the "chimpanzee in the sky" (he often looked skyward which suggested that this is where he was directing his behavior). He eventually stopped his display when the thunder didn't abate, his behavior similar to when one male submits to another.

I agree that the range of responses suggest a good deal of cognitive and behavioral flexibility. Much like in humans, the response to the death of a loved one often depends on each individuals temperament and personality. In fact, if the behaviors were always the same it would probably mean that the experience wasn't as emotionally painful as these examples suggest.

Anonymous said...

About 5 years ago I shot a grey squirrel, one of a pair, around 1PM, from the canopy of trees on the edge of my plant nursery. These squirrels are an introduced species here... and have become quite successful as a gregarious & inventive nuisance to me and other species hereabouts... notably the smaller native Douglas squirrel (which don't bother my seedling trees to any great degree).
It was a young male. For many days afterwards the 'other' squirrel came to the place of the killing and made a particular (rather mournful) call at approximately the same time of day. I came to associate that behavior with a form of mourning, as it lasted so long & seemed to go well beyond the "what went wrong, here?" behavior... & I suppose this is anthropomorphizing (but, how much, I wonder?). ^..^

Anonymous said...
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Anonymous said...

This is moving and poetically written, and I really like your use of historical material here. But I've got a concern about your scientific content.

I'm not sure what the chimpanzee did can only be described as mourning. Yes, she is coming to understand that the infant she feels such a bond to has changed. But human mourning runs deeper than a merely pragmatic investigation of a material change. Unless I missed something in my quick read of the paper, I'm not even seeing an indication of emotional loss (although that wouldn't surprise me). But what I'm definitely not seeing is the prospective, retrospective, or social dimensions to mourning. I'm only a layman, but it seems like our evidentiary standard for projecting human behavior onto non-humans has to be very high, because it's so tempting.

I'm also surprised that care of the sick is still a theoretical challenge. It has seemed obvious to me since The Selfish Gene came out: altruism genes incline their host bodies to care for other bodies likely to have the gene. A species by definition shares a lot of genes. A general inclination to care for things the more they are like you and your tribe would be a parsimonious way to achieve that. Competitive, anti-gaming, and survival instincts would work against that, but those shouldn't be relevant in caring for the sick.

I'd love to read more on the current thinking on this, but the link to Douglass-Hamilton's paper is broken. Would you have a title handy?

Eric Michael Johnson said...

Thank you 300baud. Here is a corrected link for the paper "Behavioural reactions of elephants towards a dying and deceased matriarch" (we will fix the broken link above, thanks for pointing that out).

I've worked closely with great apes in my graduate work and am always concerned about the temptation to anthropomorphize. We should not interpret this mourning behavior in chimpanzees as reflecting the same internal state as humans experience. However, we should think of it as a difference in degree rather than a difference in kind. Frans de Waal has warned against what he terms anthropodenial (see, for example, his book Primates and Philosophers). Given that we share between 98.6 and 99.4 percent of the same genes with chimpanzees and bonobos, the most parsimonious interpretation when encountering similar behaviors within the same context is that they emerge for similar reasons. These conclusions should be tentative but should inform future behavioral studies so that they can be explored more fully.

The theoretical problem of helping an unrelated sick or dying individual is that altruistic behavior that helps another but which causes the actor to incur a cost would not promote the actors reproductive success (making it less likely that genes promoting this behavior would be widely spread through the population). Hamilton proposed a solution with his kin selection theory which is what Dawkins was referring to when he discussed human altruism in The Selfish Gene. The idea is that any gene that promoted altruism wouldn't spread through the population if it didn't enhance an individuals fitness. But if it benefitted a close kin member such genes would still have a good chance of spreading more widely. Dawkins argued that these "altruistic genes" evolved in our hominin ancestors who lived in small communities composed of close kin and don't realize that many of us now live in societies composed mostly of strangers. Trivers proposed an alternative explanation with his reciprocal altruism theory arguing that costly behaviors that helped a stranger could be fitness enhancing so long as such behaviors were paid back (the most well known example of this is in vampire bats who regurgitate blood into the mouth of an unrelated group member and receive similar support on nights when they are unsuccessful). There has been a great deal of interest in this topic during the last few years since a number of studies have found these explanations to be incomplete. I have written extensively on these topics and have linked to a few of my relevant posts below.

- Punishing Cheaters Promotes the Evolution of Cooperation
- Chimpanzees Prefer Fair Play To Reaping An Unjust Reward
- The Sacrifice of Admetus
- The Bonding Brain
- Helpful Cichlids in the Gladiator's Show
- The Struggle for Coexistence

Raymond Vagell said...

The link has been corrected. Here's the hyperlink in case you don't want to find it in the post.

Behavioural reactions of elephants towards a dying and deceased matriarch: