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Comments and concerns over the Dan Povinelli Cross-fostering Project

Roger Fouts

There are several concerns I have about the Povinelli project as it is has been stated in the press. Apparently Povinelli wants to cross-foster eight chimpanzees with the expressed hope to find out what they don't do, or can't do as compared to humans. The accounts state that the chimpanzee babies will be taken from their natural mothers and then raised for 4-5 years and then abandoned by their adoptive parents to be introduced to a chimpanzee group. In my professional opinion there are three major areas of concern, they are breeding, humane research and the efficacy of such research for its reported aims.

1. Breeding

At present there is a moratorium on breeding chimpanzees at the federal level. It is estimated that of the approximately 1600 chimpanzees in biomedical facilities nearly half of these are surplus. The problem has been addressed and solutions ranging from killing the surplus chimpanzees to creating retirement sanctuaries have been suggested. The latter seems to be the one that is gaining the most favor at present. Since the moratorium exists for federal projects, then it seems reasonable to assume that the babies Povinelli wants would have to be bred specifically for his program. Certainly, I would not think that given the surplus problem that New Iberia would be breeding chimpanzees willy-nilly. So unless I misunderstand the surplus problem, this means that eight more chimpanzees would be bred into a situation where the main problem is to find a humane solution for the hundreds of chimpanzees presently considered to be surplus.

If Povinelli's goal is to produce a humane facility for chimpanzees there are hundreds who badly need a home. It is beyond me why he would want to breed more into the present surplus situation.

Another problem is that Povinelli has stated that he plans to use babies who have been "rejected" by their mothers. I am curious as to how many babies will be bred into the this surplus situation before he finds eight mothers who will reject them? And I am also curious about the husbandry at New Iberia if they encourage breeding by mothers who are known to be poor mothers who reject their infants?

2. Humane Research

It is well known that abandonment or loss of a parent can have devastating, if not lethal effects on the infants. In Povinelli's proposed project these infants will suffer double losses. First, they will be taken from their biological mothers, and then the parents who raise them for 4-5 years will abandon them. Jane Goodall provides one of the more dramatic accounts of this when 8 year old Flint mourned himself to death after his mother Flo died. Also, it is quite common for free-living chimpanzee infants to die when they have lost their mothers, even when they are adopted by other chimpanzees. Over the past 33 years I have experienced a similar phenomenon with regard to separation and loss among young captive chimpanzees. The following are some of the examples I have observed.


Maybelle was nearly five when I first met her in 1970. She was being cross-fostered in Oklahoma and her mother was a single woman who had never left her. About six months later her mother decided she was old enough to leave to attend a convention in California. A few days after she left Maybelle became extremely ill and in four days had died. Her symptom was extreme diarrhea. Even though a medical doctor and veterinarian treated her, other than the intestinal problem no specific cause of death was determined.


Salome was born July 7, 1971 and was cross-fostered by a couple in Oklahoma since she was a few days old. When Salome was 6 months old her human parents had their own daughter who was raised with Salome. When Salome was more than a year old her parents decided to take a vacation. A few days after they left Salome became extremely ill. They were informed about Maybelle and they knew that this might be serious so they rushed home and Salome recovered. About 18 months later they decided to try to take another vacation without Salome. Salome became extremely ill again with diarrhea, but his time her parents did not return in time to save her and she died.


Ally was born October 15, 1969. He was taken from his biological mother and given to a single woman to raise. I first met him in 1970. When he was nearly five- years old his human mother returned him to the Institute for Primate Studies to be introduced and integrated with other chimpanzees. He went into a severe depression, stopped eating, plucked all his hair from his body, suffered from diarrhea and lost the use of one arm. Only after several months of giving him constant human care did he begin to adapt. But he never seemed to regain the confidence and poise he had evinced before the trauma. In the early 1980's it was reported that he was sent to a biomedical facility, and even though I have been unable to confirm this I was told that he was killed in lethal testing of insecticide.


Lucy was born on January 18, 1966. She was cross-fostered by a couple with a teenage son since she was two days of age. I first met her in 1970. When she was 12 years old her human parents decided to send her to Africa in hopes of placing her in a sanctuary there. They bought another adolescent chimpanzee to be her companion and hired a student to accompany her to Africa. She stopped eating, and lost her hair and evinced classic signs of depression. Once again, only intensive human care seemed to help her survive the separation. She was finally placed on an island with other chimpanzees under human care. She was killed by poachers when the human caretaker was absent.


Moja was born November 18, 1972 and was taken from her mother and sent to Reno, Nevada to be raised by R. Allen and Beatrice Gardner until they sent her to be integrated with other chimpanzees at the age of 7 in December 1979. They sent one of her human companions with her to spend a month helping her to adjust. She went into a severe depression which resulted in her grooming a small sore on her leg to the point of where bone was exposed. She picked her hair off in spots. She stopped eating anything except peanut butter sandwiches. Again it was only after intensive human care that she become integrated with other chimpanzees and begin to eat again. And it was nearly 15 years later that she has seemed to recover from the trauma and began to show confidence and began to lose some of her neurotic symptoms. Yet even today, 20 years later, when she is under stress she will display twitching movements and occasionally coprophagy.


Nim was born in November 1973 and was sent to New York as a part of a language project. It was not a cross-fostering experiment because he had over 55 different trainers in the three years and 10 months of the project before he was returned to Oklahoma. Nim did show some depression, but it may have due to more the move than any parental separation.

Dar and Tatu

Dar was born August 2, 1976 and Tatu was born December 30, 1975. Both were raised by the Gardners, as was Moja, in a cross-fostering study until May 1981 when the were sent to Ellensburg, Washington to be integrated with Washoe, Moja and Loulis. They were raised together in Nevada and were accompanied by human companion. Both of the chimpanzees displayed distress at the separation and move. Tatu would rock and suck her thumb. Dar's response began as aggression and turned into withdrawal. It was more then a year until they seemed to adjust, and even today Tatu will rock or rock-walk when upset. The fact that they were bonded and came together may have reduced some of the trauma associated with separation.


Washoe was wild-captured and is estimated to be born about September 1965. She was cross-fosted by the Gardners from the time she was approximately 10 months of age in Reno from June 1966 until October 1970. I was one of Washoe's human companions and have been with her continually since September 1967. In October 1970 I accompanied her to Oklahoma and in 1980 I accompanied her to Ellensburg Washington. She is one of the few cross-fostered chimpanzees I have know who did not evince severe trauma at separation. This may be because I was a stable member of her family in Reno and have stayed with her since.

Implications for the Povinelli project

The Povinelli project is clearly not original and appears to be redundant with previous cross-fostering studies. In addition to the above studies it should be noted that the cross-fostering research has been done many times. Some of the more well known studies are those of Nadia Kohts with Joni, Kellogg and Kellogg with Gua, and Hayes and Hayes with Viki. The Gardner's have published extensive research comparing cross-fostered chimpanzees to free-living chimpanzees, lab-reared chimpanzees and human children. I would be very curious to know if the Povinelli proposal has taken into consideration the wealth of information already existing in the literature.

I have worked with cross-fostered chimpanzees for more then 30 years and I can assure you that using the word "cross-fostering" does not guarantee the quality of the cross-fostering, no more than does using the word "parenting" ensure proper parenting. The quality of the cross-fostering will depend on the dedication and time the foster parents wish to devote to a child who is not of their species. There is great variability in this and considering the fact that foster parenting is not a life-time, but only a 4-5 year commitment, this selects against finding truly dedicated people who are willing to give the amount and quality of care an infant chimpanzee needs. It has been my experience that infant chimpanzees not only seem to need more care than humans do, but they demand it. So I am not sure that the parents who would choose to only care for a chimpanzee for these few years are the same as a parent who is willing to dedicate their life to raising a child. However, regardless of the quality of the cross-fostering we humans can never be a competent chimpanzee parent. In the end, we will be responsible for creating a child who will never be integrated into human society, and at best will become a misfit in chimpanzee society.

Free-living chimpanzees are often not weaned until they reach the fourth year of life. They don't begin to move away from the mother for long periods of time until they are about nine, and generally do not have their first offspring until about 13 years of age. A four-year-old chimpanzee will still have his or her milk teeth. They are very dependent on their mothers. This means that the Povinelli study will take place entirely in infant and pre-adolescent chimpanzees. The abandonment of such a young chimpanzee can have devastating effects on the child, as already noted by Goodall among wild chimpanzee children who have lost their mothers as well as in the deprivation studies done in captivity.

All this evidence points to the very high probability that the end of Povinelli's experiment will have a devastating effect on the psychological well-being of the chimpanzees involved when they are abandoned by their human foster parents. This does not mention the potential devastation that the natural mothers will suffer when their babies are taken from them.

3. Negative evidence and scientific efficacy

I have another concern about a violation of a basic tenet for science. It is commonly taught in any beginning psychology or statistics course that you cannot prove the null hypothesis. If you do not find a positive result you cannot assume that something is not there, the best you can do is to withhold judgment. To do otherwise would be to confuse the absence of evidence with evidence for absence. The history of science has told us repeatedly that such an approach wastes time and energy that could be put to better uses. Povinelli is not unique in making this error, but it is quite common when you consider other positions that have come from this flawed approach such as: "Man is the only animal who possess rational soul," "Man is the only animal capable of thought," "Man is the only animal who uses tools," "Man is the only animal who makes tools," and the list goes on. Historically, these hypothesized "gaps" in the phylogenetic scale have turned out to be "gaps" in the scholarship and in the minds of the people who practice them.

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