View Our Catalog

Join Our E-Mail List

What's New

Sign Language Studies

American Annals of the Deaf

Press Home

Show of Hands: A Natural History of Sign Language
Previous Page

Next Page

As early as 1909, the French sociologist, Robert Hertz, attempted to account for aspects of the cross-cultural right/left dual symbolism by reference to Broca’s work on the neurology of handedness and language. What is striking about this cross-cultural literature is the near universal association  of the right with positive and the left with negative attributes. In English, the word dexterous comes directly from the Latin word for right, while sinister is derived from Latin for left. From cross-cultural studies of right/left symbolism compiled by the anthropologist Rodney Needham (1973), we find such widely distributed associations as these:
  • Right—strong, social order, senior, esteemed, auspicious, life, eating
  • Left—weak, disorder, junior, hated, inauspicious, death, eliminating
Hertz sums up the difference in the following terms:
What resemblance more perfect than that between our two hands! And yet what a striking inequality there is! To the right hand go honors, flattering designations, prerogatives: it acts, orders, and takes. The left hand, on the contrary, is despised and reduced to the role of humble auxiliary: by itself it can do nothing; it helps, it supports, it holds. (1973, 3)
How, then, did the hand, especially the right hand, come to occupy such a central place in so many aspects of human behavior? In his influential book, The Hand: How Its Use Shapes the Brain, Language, and Human Culture, the neurologist Frank Wilson summarizes the essential anatomical adaptations of the primates that made them successful tree dwellers:
  1. orbits and eyes moved to a forward position in the head, permitting binocular vision, certainly an advantage for navigating in three-dimensional space and for finding and catching small prey at close distances;
  2. forearm and collarbone structure were modified to permit greater flexibility and perhaps greater safety in arboreal travel and dining;
  3. paws that retained the archaic but extremely useful fiveray (pentadactyl) pattern, permitting the animal to grasp with individual digits; toes and thumbs acquired the ability to close the gap between the thumb and first digit (i.e., they became convergent, though not yet opposable); nails replaced claws on the dorsal surface of terminal digits, while palmar surfaces acquired sensitive, ridged pulps—all these changes permitted improved climbing and locomotion along trunks and branches, and better grasping and holding of fruits, leaves, and insects;
  4. the snout shortened, vision began to supersede smell as the dominant sense, and jaws, skull, and teeth changed, consistent with dietary change; 5. the brain changed in size and configuration, probably to accommodate the geometrically more complex living and hunting environment. (1998, 19–20)
The central thesis of Wilson’s book is that the nexus implied here between powerful binocular vision and hands capable of fine manipulation set the stage for the eventual evolution of human beings as makers and users of tools and as successful communicators through visible gesture. Within the primate order, it was human beings who took greatest advantage of this potential for coordinated activity involving hand and eye.

At some point during the evolutionary history of the primates, the hominoids, the superfamily to which humans and apes belong, developed a further specialization related to locomotion. This has been called brachiation or brachiation with “knuckle-walking.” This mode of locomotion involves hands with relatively long, hooklike fingers and short thumbs. Apes can thus move through trees by arm-over-arm swinging or by grasping tree limbs from underneath with their hooklike  hands and prehensile feet, rather than by running along the upper surfaces of branches like monkeys. On the ground, apes, especially chimps and gorillas that spend much of their time out of the trees, walk on the knuckles of their hands, not the palmar surfaces. However, given their elongated fingers and short thumbs, apes have difficulty bringing their thumbs into full opposition with the palmar surfaces of their fingers—thus, limiting the extent to which they can form precision grips, a hallmark of the human hand.

We should, then, look closely at the anatomy and function of the human hand, within the context of its recent evolutionary history. Very early in the hominid (now often referred to as the hominin) lineage, the lineage leading to modern humans, the evidence concerning the evolution of the hand indicates that the following functional capabilities, characteristic of modern humans, seem to have emerged:

  • the thumb, index, and middle fingers can form a “three-jaw chuck,” which means the hand can conform to, grasp, and firmly retain irregular solid shapes (such as stones);
  • finer control can be exerted over objects held between the thumb and the tips of the index and middle fingers;
  • rocks can be held within the hand to pound repeatedly on other objects (nuts, for example), or to dig for roots, because the new wrist structure is able to absorb (dissipate) the shock of repeated hard strikes more effectively than in the ape hand. (Wilson 1998, 26)

Previous Page

Next Page