[tompe]

Originally Posted by j.p.s

Just today, I heard a claim (which I do not accept) on Radio Lab that people do not begin thinking until they think in words.

Probably Sapire-Whorf:

http://en.wikipedia.org/wiki/Linguistic_relativity

The principle of linguistic relativity holds that the structure of a language affects the ways in which its respective speakers conceptualize their world, i.e. their world view, or otherwise influences their cognitive processes. Popularly known as the Sapir–Whorf hypothesis, or Whorfianism, the principle is often defined to include two versions. The strong version says that language determines thought, and that linguistic categories limit and determine cognitive categories, whereas the weak version says only that linguistic categories and usage influence thought and certain kinds of non-linguistic behaviour.