A Chimpanzee with No Legs Cannot Hear

[A draft from years ago that I never posted. Just clearing out by draft folder.]

There would be little media attention (or grant money) if researchers published a paper and said that it was just more of the same and demonstrated yet again what has been known for nearly a century. Much better to claim that it is a "first of its kind."

Nurtured chimps rake it in
June 14, 2007

Human interaction and stimulation enhance chimpanzees’ cognitive abilities, according to new research from the Chimpanzee Cognition Center at The Ohio State University. The study* is the first to demonstrate that raising chimpanzees in a human cultural environment enhances their cognitive abilities, as measured by their ability to understand how tools work. The findings have just been published online in the Springer journal Animal Cognition.

The scientists compared three groups of chimpanzees: one with a history of long-term stable, social interaction with humans (‘enculturated’); a group raised in a sanctuary setting, with only caretaker contact with humans (‘semi-enculturated’); and another group raised under more austere captive conditions (laboratory chimpanzees). The experiments looked at how the chimpanzees used rakes in order to retrieve a fruit yoghurt reward. The overall study examined not only whether the chimpanzees understood the properties of the tool, but also whether they understood the reasons why the tool worked....

*Furlong EE, Boose KJ, Boysen ST. Raking it in: the impact of enculturation on chimpanzee tool use. Anim Cogn. 2007 May 22.

Are you familiar with the old joke about the scientist dismembering the grasshopper?

Scientist: "Jump grasshopper jump!"
Grasshopper jumps and scientist records: GH with 6 legs jumps 24.71"

Scientist pulls off one leg. "Jump grasshopper jump!"
Grasshopper jumps and scientist records: GH with 5 legs jumps 19.23"

Scientist pulls off another leg. "Jump grasshopper jump!"
Grasshopper jumps and scientist records: GH with 4 legs jumps 12.03"
.
.
.
Scientist pulls off 5th leg. "Jump grasshopper jump!"
Grasshopper jumps and scientist records: GH with 1 leg jumps .16"

Scientist pulls off last leg. "Jump grasshopper jump!"
Grasshopper doesn't jump. "Jump grasshopper jump!" Grasshopper still doesn't jump. Scientist pounds table. "Jump grasshopper jump!!" Grasshopper just lies there.

Scientist records: GH with no legs cannot hear.

Like this little allegory, the scientists studying the chimpanzees conclude: "These results provide the first empirical evidence for the differential effects of enculturation on subsequent tool use capacities in captive chimpanzees."

First, this isn't the first empirical evidence of a disparity between enculturated chimpanzees and chimpanzees living in deprived settings.

And second, the conclusion misses the actual phenomena demonstrated in their study.

The earliest empirical evidence regarding the wide disparity in tool use or tool mastery between enculturated chimpanzees and deprived chimpanzees, of which I am aware, can be found in The Ape in Our House (Cathy Hayes. Harper and Brothers; New York: 1951.)

In 1947, Cathy and Keith Hayes were given an infant chimpanzee by Yerkes Laboratory of Primate Biology director and chimpanzee vivisector, Henry W. Nissen. They named her Vicki and raised her as their daughter. The experiment with Vicki was the reason that the Hayes had moved to Orange Park Florida, where Robert Meanes Yerkes' primate colony had been established following its move from Yale. Keith Hayes was employed by the Yerkes laboratory as an experimental psychologist.

Vicki Hayes' developmental progress was closely monitored and recorded through at least the first five and a half years of her short seven and a half year life. (I have yet to find an explanation for her apparent early death.)

Vicki was filmed in a variety of situations. Her time with the Hayes is very well documented.

The Hayes' work with Vicki seems a clear anticipation of the Ohio State University claim. it does not seem that their study is in any meaningful way "a first."

Problem 1. This was a tunnel made of heavy screening, in the middle of which could be seen a gaily wrapped prize. Nearby was a long stick.

The first subject, Cassie, was given two minutes to see if she could figure it out for herself. When she told us that she could not get it, I asked "Shall I show you?" ...

Her little friends, Alice and Kathy, also had to be shown. Then, after much fingering of the apparatus, and shy smiling at the experimenter, they solved [the problem] as Cassie had.... the sole boy subject, Alan, was so fascinated by the equipment itself that after he had earned his prize, he did not open it, but put it back in the tunnel and poked it out again and again.

Vicki performed quite like the children, taking a similar length of time.

Frans, the laboratory chimpanzee, was hopeless. No amount of demonstration helped him, although he wanted his reward of fruit very much. Later, the experimenter guided Frans' hand through the proper movements, thus going beyond the demonstration, and aiding him to have the experience himself. This encouraged Frans to wriggle the stick aimlessly if someone put it into the tunnel for him, but he never did learn to make it move in the right direction. This problem, therefore, told us nothing about his imitative ability. He could hardly be expected to learn by imitation what he could not learn by direct experience. (Other work has shown that because of his lack of experience with sticks, Frans is unable to solve even the most elementary problems which require the use of a stick as a tool.) (pgs. 184-185 passim.)

The Hayes account and the Ohio State account both seem to demonstrate the effects of deprived environmental stimulation (and socialization) written about by Rene Spitz, John Bowlby and others throughout the 1900s. This seems a more likely factor than some special benefit associated with being raised like a human or around them. (Our god-like glow is a gift to all.)

It is unlikely that the deprived chimpanzees would have the same repertoire of tool use as wild chimpanzees benefiting from an intact cultural system and rich opportunity to observe and practice.

More recently, it has been observed that some of the Romanian orphans created by the dictates of Nicolae Ceausescu continue to have significant cognitive deficits. (Beckett C, Bredenkamp D, Castle J, Groothues C. O’Connor TG, Rutter M, and the English and Romanian Adoptees (E.R.A.) Study Team. “Behavior Patterns Associated with Institutional Deprivation: A Study of Children Adopted from Romania.” Journal of Developmental and Behavioral Pediatrics 2002; 23(5):297-303.)