GIBBON VIDEO NOTES (with a note on C.R.Carpenter)

(revised, 3/03/04)


1 Clarence Ray Carpenter

Carpenter, C. R. (1940). A field study of the behavior and social relations of the gibbon (Hylobates lar). Comparative Psychology Monographs, 16(5), 1-212. (Reprinted in Carpenter, C. R. (1964) Naturalistic behavior of nonhuman primates. University Park: Pennsylvania State University Press.

Carpenter was a comparative psychologist. His research, earlier with pigeons, then monkeys, concerned sexuality and social relationships. His gibbon work was supported by a private foundation (as was all research in those days)--The Committee for Research in Problems of Sex. Robert Yerkes had been chairman of this committee and supported Carpenter's research.

(See Haraway, 1989, pp.70-71 and ch. 5) His last work was on control of aggression.

Previously the "Committee" had looked to "primitive" human cultures to learn about the original human condition regarding sex but this came to be seen as hopeless. Non-human primates seemed more promising. Carpenter's views fit right in:

".....there are basic human needs, drives, and types of behavior which have elements in common with similar functions of the non-human primate level. For example many aspects of sexual behavior are similar in man and the apes. Perhaps in these primates one may observe anlagen (approximately basic "plan" or "blueprint", JL) of human motivation and behavior, free from cultural veneers and far enough removed to avoid the well-known errors involved in man's study of himself. (Carpenter, 1940/1964, p. 160)."

Carpenter seems to have had a very sophisticated view of the relationships among social structure, sexual activity, and communication. Gibbons made good subjects for his research. Though the assumption that humans and gibbons were equivalently monogamous is not true. They do share some common features, however, including extensive pair-bonding, high male concern for young, and melodic vocalizations between males and females unlike any other ape.

Carpenter provided some of the first specific data on periodicity in sexual activities for monkeys and that female's sexual interest and solicitations increased near ovulation. (Dixon, 1998)

Today there is much more interest in bonobo sexuality than that of gibbons.


2 Gibbons (Hylobates xxxx)

There are about eleven varieties of gibbons and simangs, all known as Hylobates xxxx. In the Carpenter film, they are the common Hylobates lar. Gibbons are found in fairly large numbers throughout southeast Asia -- once also the habitat of the much larger orangutan. Gibbons relative success may be due to their much smaller size. (This is not to say the gibbons are doing well; their habitats are being drastically reduced everywhere.)

A. the smallest and most distantly related ape

Gibbons eat fruit (60%) and leaves (36%), with a small percentage of insects (4%). They weigh about 24 pounds.


B. extremely agile, upright posture, Asian tree-dweller

Their long arms are obvious as is their terrific gymnastic ability.

C. unique social structure--territorial and monogamous

They live in small groups, a male and female, with up to 3 dependent offspring. There is very little if any sexual dimorphism. The young go off on their own at about nine years and generally form a life-long relationship with their mate and establish territory in their forest.

They define and defend this territory with loud vocalizations.

(It remains to be seen if DNA evidence will reveal a degree of "unfaithfulness" as it has in some monogamous bird species!)

Females have a cycle of 27 days, with swelling and color changes in genitalia. Like many other primate species, the female has a considerable control or "choice" over when mating occurs.

A single offspring is born after a gestation of about 7 months; weaning occurs after two years and interbirh intervals are about three years. Gibbons may live twenty to more than thirty years.

D. controlled vocalization --the other "singing ape"

The film suggests the controlled nature of gibbon calls contrasted with the grunts and hoots of chimps. It is curious that long-term female-male bonds are found in highly vocal species including parrots, gibbons, and humans. (Bonobos, too, are relatively vocal for apes.)

Gibbons are noted for their loud "duets" in which males and females alternate melodic calls. These serve similar functions to bird song including defining territory and enhancing social bonds between pairs.

3 the film

the film was taken in the Carribean, Hall's Island?. Obviously this is not a natural habitat for gibbons. Carpenter pioneered film as means of studying behavior. In wartime, 1940s, he developed military uses of film and afterward helped set up the important primate film archives at Penn State.


A. play

1 social and individual

2 the play face

3 "reciprocal inhibition" with aggression

4 activities

1 wrestling, chase, copulating,

5 functions

1 develop new action patterns?


B. copulation

1 social function in addition to reproduction. Sex as an integrating factor in social relationships--including reduction of aggression-- has been an important theme for Carpenter and others studying primates. See the readings by deWaal on Bonobo chimps and Small's interesting book on "Female Choice."

Small, M. F. (1993). Female choices: Sexual behavior of female primates. Ithaca: Cornell University Press.


C. vocalizations


1 distant and close calls

2 group function

3 interpersonal function

4 the missing referential function?

Human communication is notable in that we not only convey emotions, build and maintain social relationships, but we talk about things--both abstract (e.g. beliefs) and concrete (e.g. pencils). The vervet monkeys have received lots of publicity recently as being one of the very few examples of naturally occurring referential communication in nonhumans--as far as we know. (See Cheney and Seyfarth's book on vervets; other examples were seen in "animal intelligence".)

Cheney, D., & Seyfarth, R. (1990). How Monkeys See the World: Inside the Mind of Another Species. Chicago: University of Chicago Press.


What makes human language unique is its "open" nature (new words are invented), its "creativity" (virtually every phrase we use is a novel one and we can spontaneously form new referential phrases out of existing words --e.g. what's that thing with a yellow skin and brown spots on it? Finally the formal structure of phrases involves several levels of hierarchically organized basic elements -- features, phonemes, syllables, morphemes,...

5 the missing individual function of language?

Human language (which is NOT IDENTICAL with human communication) also serves us personally in aiding our thought and memory processes, controlling actions (e.g. following a recipe or learning to tie shoelaces), and perhaps is responsible for some aspects of our consciousness?

Watch the relationship between young non-human primates and their mothers and contrast that with the increasing importance in vocal and linguistic communication between human infants and their families.