Stone handling and us

image source: http://www.pri.kyoto-u.ac.jp/shakai-seitai/seitai/newpage12.htm
(the link broke, so I am now providing a local copy of the picture)

We were told that these Japanese macaques hoarded rocks for no apparent reason; that the behavior was culturally transmitted; and only observed in troops of monkeys living around long-term feeding stations. This factoid provoked much more thought than whatever talk or lecture it preceded -- so much so that I don't even remember the content of that talk.

First some more information about this behavior, then some speculation on how I think the behavior may relate to us.

More info
The behavior is termed 'stone handling' by its initial observer, Michael Huffman of Kyoto University. I read more about it in in a paper by him in the book, "Social Learning in Animals" (Heyes and Galef, eds.; Academic Press, 1996). (Nice for me that Harvard has a big library -- it had this book.) The paper is titled "Acquisition of Innovative Cultural Behaviors in Nonhuman Primates: A Case Study of Stone Handling, a Socially Transmitted Behavior in Japanese Macaques".

Decades ago, feeding stations were built near forests in Japan containing troops of macaque monkeys, for the purpose of drawing the monkeys out of the forest so that humans could conduct long term observational studies of monkey social networks and behavior. A National Geographic article (Feb. 6, 2004, by Bijal Trivedi) states that these feeding stations are the main food resource for these monkeys, though this was not made explicit in the paper. For these well-fed monkeys, stone handling emerged as a common behavior in five culturally isolated troops, most commonly observed in younger members of the troop. From Heyes and Galef, p.273:

  After further investigation, the circumstances under which the behavior most frequently occurred became clear. As a rule, stone handling is most frequently observed immediately after feeding time, during a period in which individuals usually rest, play, or engage in grooming activities. Individuals seen stone handling always have their cheeks filled with grain and show no signs of distress or other abnormal emotional expressions. Stone handling usually continues until all the grain the cheek pouches has been ingested.
  The stones appropriate for handling can be found almost anywhere in the forest and the brush surrounding the feeding area. Even though there is nothing particularly striking about the stones used in handling to the eye of the human observer, nearby monkeys will approach, and in some cases, snatch the stones away from a handler. It is quite common when another monkey approaches, for an individual handling stones to pick them up and move to another area to resume the activity. Quite frequently, nearby individuals will pick up stones left behind and begin to manipulate them as if they were the only stones available. Attention appears to be draw to the stones simply because others are manipulating them.

Heyes and Galef, p. 285:

  However, as the study of stone handling suggests, it is not necessary for a behavior to provide tangible benefits in order for it to be passed from one generation to the next. Stone handling can not be explained in terms of contribution to reproductive fitness or facilitation of subsistence activities. ... it is possible that there are less direct benefits of the behavior. Reminiscent of worry beads [e.g.] or pocket-sized rubbing stones used by humans in some cultures, stone handling itself may be relaxing or stimulating and thus its benefits could be psychological or physiological in nature.

Speculation
It can be adaptive to collect resources even in times of abundance. Taking advantage of good times to hedge against lean times is largely what adipose tissue is for, not to mention grain silos. I think that primates (including us!) are constitutionally disposed toward gathering, hoarding and stealing resources even in times of abundance. In these macaques, there is no reason to hoard food -- they have as much as they need, free at hand. Does this sound familiar? It is the condition most of us in the Western world live under. Yet the basic impulse, to constantly be hoarding and acquiring, persists, and finds relief in unrelated activities, like buying useless stuff, overworking, and pursuing other apparently reproductively irrelevant ambitions. I wouldn't be surprised if the entire Industrial Revolution, in some sense, is a direct result of the same urges that drive these macaques to stone handling.

On Fri, Jan 28, 2005 at 10:32:05AM -0500, hugh dengler wrote:
> google language tools, eh'? stone handling, eh'? very nice, very nice...
> hoarding mentality you think hmmm?
>
> so you think that because the handling happens only around feeding time,
> that it has to do with hoarding even in times of abundance? why wouldn't
> they just hoard the food?

I think they're not smart enough -- too much advance planning required for stashing stuff -- squirrels do it by instinct but monkeys as far as I know are just grazers (though I could be wrong)

> or are you implying that it's some sort of
> triggered response? like a particular part of their brain (the part
> specific to this hoarding mentality) gets tripped as a response to feeding,
> which is a basic subsistence instinct, and then gets carried over to other
> objects or behaviors?

Yeah I bet that it gets tripped because when a pack (dogs, seagulls, monkey troop, etc.) finds a food resource, it's always a point of contention who gets the good stuff, or the most stuff. And lots of competition and eyeing other pack members' food and so forth. And when the resource is nearly unlimited, this urge gets triggered, but they all have plenty of food, so the urge finds another outlet

> something something... hmmm... hmmm... monkeys,
> eh'? maybe they just like the rocks. maybe they're just playing with them
> as part of the rest and play time following a meal. the way a dog likes to
> chase a stick I say.
>

Yep, could be. I was mostly interested in the idea that it can be adaptive to continue striving and struggling even when you have everything you need, and so many people may be constitutionally prone toward restless worrying, acquisitiveness, and ambition. I think this restlessness in the face of plenty permeates our entire culture, for better and for worse. And maybe it comes from this old compulsive instinct, which makes us feel that if we are *not* working and struggling, we are not doing enough to prepare for hard times to come. Only by working and struggling can we relieve the pressure of this instinctive compulsion, even if our work and struggle has nothing to do with actual survival.

Whether or not the stone handling in the macaques is a manifestation of the same compulsion, I don't know. It just triggered this thought about how we are structured, and why many of us seem to struggle so much, and work so hard, even after our basic survival requirements are abundantly fulfilled.

A positive feedback cycle emerges. We receive social affirmation and status for attaining these arbitrary things, and from being strong enough to guard them from other primates who want them. They cease to be entirely valueless! And so, allocating surplus effort to acquiring whatever it is that other people want becomes an asset in mate selection and other status-influenced elements of fitness.

I don't know how much I believe this idea, but it's interesting. Surplus effort <--> sexual selection.

Are you concerned that so many of the deals you're involved in just move money around and don't build value?
That's the P.R., but it isn't true. I'm not closing the company down. I am making it more productive. I am not taking money out, but bringing money in by buying stock. I don't own a private jet bought with the company's money. I don't play golf.

What do you have against golf?
I think it's a waste of time. I work a lot. I work hard. I like to work. Maybe I like it too much.

What do you do when you want to relax?
I work!

What's the point of having so much money if you can't enjoy it? I'm sort of an obsessive person. I think you have to be obsessive to be successful. You've got to be willing to work hard. My father was never that much of a worker. I don't know why.

What did your dad do for a living? He was a lawyer, but he didn't practice. He only cared about music. He liked to sing. He never got into the Metropolitan Opera, but he became a cantor at a conservative synagogue not far from our home in Queens.

You describe him as an underachiever, but I would imagine that being a cantor is very rewarding work.
You don't understand. He wasn't religious. He was an atheist. It was strange.