Hammers, flakes, and nose-thumbing devils

It smacks of some sort of wacko fetish. I’m standing in a Boston T station watching thumbs as people weave through the mass of train-waiting commuters. I must say, it’s tough to see many people’s thumbs when they’re covered in gloves. Boston got 10 inches of snow the day I flew in. But that does nothing to explain why I’m here ogling people’s primary digits.

I am on my way to volunteer as subject in a Harvard anthropology PhD student’s Hand Biomechanics During Simulated Stone Tool Use study (www.fas.harvard.edu/~skeleton/rolian.html). Through his thesis, Campbell Rolian intends to reveal new significance in the evolution of the thumb. Since I myself am a thumb-centric grad student (Who the thumb am I?), I thought why not mix in my thumbs with all the others he’s observed for his data?

He meets me near the Mayan Peoples exhibit in the Peabody Museum at Harvard. The Anthropology Dept. is on the fifth floor, above the Museum of Natural History. He conducts his tests in the Skeletal Biology & Biomechanics lab 55E. The narrow room’s walls are lined with shelves of books and equipment interspersed with dry erase boards covered with inky equations, lists, and outlines.

Campbell trains six infrared cameras on me as I sit in a simple chair in front of a newspaper-covered coffee table. Perhaps my time in the Museum of Natural History downstairs has fueled my imagination, but I feel as if six black-nosed creatures with beady red eyes have surrounded me. Inveterate predators, they do not move a muscle, nor do they salivate as they calculate how tasty their 1/6th portion of my increasingly fleshy flanks will be. It does not help matters that I have been greased like a stuck pig. At least … my hands have been oiled. Baby oil simulates the greasiness hands would encounter as Stone Age scavenger hunters when they butchered the remains of a kill made by larger predators who had eaten their fill and moved on.

Along with the baby oil, I have 9 juniper-berry-sized plastic balls covered in reflective tape stuck to various points on my fingers, wrists, and elbow. I look as if I have sprouted silver warts. The six infrared cameras trained at my hands show where my thumb is in space when I’m hammering or flaking.

An orange institutional couch cushion sits at my feet, between me and the coffee table. The cushion is a safety net to pad the fall of the tools my greasy, shiny-warted hands might drop.

A 30-something-year-old Canadian with no shortage of close-cropped hair, Campbell lets me in on a secret. He admits that the sticky squares with which he has stuck the 4 mm reflective tape-covered balls to my fingers and wrists is actually toupee tape. According to the Hair Direct box it comes in, the tape keeps the toupee on for up to two weeks, bathing and swimming included. It comes in an unmarked box with only the letters H.D. in the return address.

We test two tools, a hammer stone and flake, both made of solid brass. The hammer contains 5 sensors: three under the thumb, two under the index finger. The computer screen registers spikes in graphs, which show voltage as a function of time. With this hammer stone tool, we are recording forces. While I hold the hammer tool with a three-jaw chuck, or baseball, grip, and the core with a cup grip, the markers on my joints show my joints’ location in space as I strike the core, which is actually the head of a vulcanized rubber mallet. The simulated flake tool has two sensors, with two markers for location of forces in space.

The sensors on the hammer stone show spikes in voltage. The spikes that correspond to the sensors under the thumb reveal that my thumbs are reacting to the force of impact, rather than anticipating or bracing for impact.

Campbell’s also looking into proportions, comparing hand size/length to foot size/length, which, to me, recalls the canon of proportions in ancient Greek art, the Rules of thumb.

What we are essentially doing is using CGI (computer graphics imaging) to test kinematics, which give us the amount of force used to strike the core. He calculates this by recording the acceleration of my strikes. He already knows the mass of the tool, so acceleration times mass equals force.

I am Campbell’s 24th subject for this portion of his thesis. Once he starts crunching the numbers from his data, I will become nothing more than anonymous subject Letter-hyphen-number, as if we had never shared personal anecdotes about baby oil and toupee tape.

In his office, down the hall and around the corner from Skeletal Biology & Biomechanics lab 55E, Campbell has a small brass fetish he bought in a marketplace in the Republic of Georgia. The figure of a cloven-hoofed, goat-horned, hook-nosed, cat-tailed devil displays the double-handed nose thumb, an archetypal gesture involving the thumb, or both thumbs if displaying the double-thumbed version. Thumbing the nose involves placing the thumb of one hand on the tip of the nose with the other fingers splayed and wiggling. According to anthropologist Desmond Morris, author of Gestures-Their Origins and Distribution: “This is thought to represent the hostile, erect comb of a fighting cock.” Or it could “relate to the ancient practice of imitating grotesque, long-nosed effigies.”

“I got it because it was so odd,” explains Campbell. “There was nothing else like it. I thought it was mocking me.”

Which is funny, because I am prrretty sure it’s mocking me.