Not only is sexuality itself a form of cultural behavior, it can also impact and intersect with other sorts of cultural innovations in primates, often in surprising ways. In fact, nonreproductive sexual activities, including homosexual behaviors, may have contributed to the development of a number of significant cultural “milestones”: hallmarks of evolutionary and cultural change that are considered to be defining characteristics of “humanness,” yet which also exist in prototypical form in some of our primate relatives (and presumably also in our protohuman ancestors). In this section we’ll briefly consider the role that sexuality might have played in the development of primate communication systems and the origin of language, in the manufacture and use of tools, and in the creation of social taboos and rituals. Caution must always be exercised in making direct comparisons between animals and people, and most of these areas are only beginning to be studied in any detail. Nevertheless, primate (homo)sexuality and the “traditions” associated with it offer us a striking mirror of some of our most “human” characteristics—and perhaps even a window into our evolutionary past and cultural history.
Language
Bonobos (also sometimes known as Pygmy Chimpanzees) have one of the most varied sexual repertoires of any species, with a wide variety of behaviors and positions used in sexual interactions, both heterosexual and homosexual. As a result, some Bonobos have developed an extraordinary system of gestural communication that is used specifically during sex. First discovered by pioneering ape-language researcher Susan Savage-Rumbaugh and her colleagues in the mid 1970s, this gestural system has far-reaching implications for our understanding of primate communication systems and the development of human language.53
A “lexicon” of about a dozen hand and arm gestures—each with a specific meaning—is utilized by Bonobos to initiate sexual activity and negotiate various body positions with a partner (of the same or opposite sex). For example, one gesture involves flicking the hand back-and-forth sideways from the wrist, meaning (approximately), “Move your genitals around”; this is used to get one’s partner to position his or her genitals so as to facilitate a sexual interaction. Another gesture, lifting the arm with the palm downward, is employed when a Bonobo wants a sexual partner to move into a facing position for copulation. A catalog of some of the other gestures is given in the accompanying illustration. Hand signals may even be strung together in short sequences, and there is some evidence that the order of the gestures is significant.54 These manual signs are used during both heterosexual and homosexual activity, although it appears that they may be more prevalent in opposite-sex interactions, and males and females may also employ some of the gestures with different frequencies.
Most of the hand signals are iconic, which means that they bear a physical resemblance to the meanings (i.e., body movements) they represent, although some are less transparently representational than others. Thus, the meaning “Turn your body around” can be related to the circular movement of the corresponding gesture, but this meaning is also conventionalized, since the intended action conveyed by the gesture must be agreed upon and understood by both participants for the gesture to be effective. An individual who hasn’t learned the gestural system, for instance, wouldn’t necessarily know what sort of “turning around” is intended by such a gesture. In conjunction with these hand gestures, a variety of positioning movements involving direct touching and placement of a partner’s body or limbs are also used to facilitate sexual interactions. Together with the more abstract manual gestures, a total of at least 25 signals used during sex have been identified. In addition, patterns of eye contact and gaze also appear to have significant communicative value.
DESCRIPTION: Arm is partially extended, hand flicks back and forth with sideways movement from wrist
MEANING : “Move your genitals around”—used to get partner to position his or her genitals to facilitate a sexual interaction
DESCRIPTION: Arm is extended, hand bends at wrist and makes rapid, vigorous circular motions
MEANING: “Turn your body around”—also used as an invitation for a sexual interaction if other methods of initiation have not worked
DESCRIPTION: Hand is held outstretched toward partner (arm extends upward and outward with palm of hand angled toward the other individual)
MEANING: “Approach”—used to get partner to move closer; also used simply as an invitation for a sexual interaction
A DESCRIPTION: Arm is extended, hand bends at wrist and flips toward self
MEANING: “Come here”—used to get partner to move closer during a sexual interaction
DESCRIPTION: Arm is partially extended and raised while hand flips upward at wrist
MEANING: “Stand up”—used to get partner to stand on hind legs before engaging in a face-to-face sexual interaction
A DESCRIPTION: Arm is extended and raised till about head level with palm facing downward and placed lightly on another individual’s back or shoulder
MEANING: An invitation for a sexual interaction
DESCRIPTION: Knuckles are rested on partner’s arm or back and arm moves back toward self
MEANING: “Move closer”—used to get partner to assume a stance compatible with front-to-back sexual interaction
DESCRIPTION: Arm is lifted up with palm down
MEANING: “Position yourself”—used to get partner to move into a face-to face position
DESCRIPTION: Hand and forearm move across body in a sweeping motion
MEANING: “Turn around”—used to get partner to rotate his or her entire body
DESCRIPTION: Both arms wave or open out from body
MEANING: “Spread your legs andlor arms”—used to get partner to open limbs to facilitate face-to-face positioning
Researchers studying the Bonobo gestural system have suggested that the more abstract hand signals may have developed out of the simpler positioning movements. 55 Communication during sex may initially have involved only fairly crude attempts to move one’s partner, from which more ritualized touching and directive gestures may have evolved, which then gradually became more and more stylized until, in some cases, fairly opaque hand gestures resulted. This sequence is significant, because it represents the sort of progression from purely representational gestures to highly codified manual signals that has been identified in the development of human sign languages.56 More broadly, it shows the beginnings of abstraction or arbitrariness—that is, the creation of symbols—which is a hallmark of human language in general. The Bonobo gestural repertoire is certainly not a “language” in the true sense of a complete human linguistic system, and by no means does it have the complexity or subtlety of even the simplest human gestural systems, let alone of a fully developed signed, spoken, or written language. Nevertheless, it is a formalized communication system that exhibits a level of sophistication unparalleled in any other nonhuman primate—perhaps even with a rudimentary “syntax” (in terms of the ordering of gestures)—and it may indeed represent a precursor to human language.