Word Play - Schlep Effect

Archaeologists use the term 'schlep effect' for which of the following phenomena? (Hint: schlep is a Yiddish word meaning "to carry clumsily or with difficulty").

1. The knot of calcium deposits noted on the clavicles of skeletons that is thought to result from a lifetime of carrying heavy objects.
2. The wide spread of exotic trade goods around central America thought to have resulted from the activities of the pochteca class.
3. The difference between faunal assemblages at field kill sites and home bases, thought to result from preliminary butchering to avoid carrying heavy inedible parts of animals a long distance.

And the Answer is....