I was reading about problems with the assumption of basic vocabulary in Lyle Campbell, Historical Linguistics: An Introduction:
Some 'basic vocabulary' appears to change rather easily for cultural reasons, for example, terms for 'head' in various languages. Proto-Indo-European *kaput- 'head' gave Proto-Germanic *haubidam/*haubudam (hence old English heafod > head) and Proto-Romance *kaput. However, several Germanic and Romance languages no longer have cognates of these terms as the basic form referring to the human head. For example, German Kopf 'head' originally meant 'bowl'; the cognate from *kaput is haupt, which now means basically only 'main', 'chief', as in Hauptbahnhof 'main/central train station'. French tête and Italian testa both meant originally 'pot'; the French cognate from Latin *kaput is chef, but this means now 'main, principal, chief', not a human head. (p. 206)
In Dutch, hoofd is still the basic word for human head, but kop is also used in some expressions and impolite usage, for animal heads as well as for 'cup'. I suppose like with German Kopf the latter is the original meaning.
Is there a reason bowl/pot/cup > head is a common semantic change (that happened independently?) in different languages? Or is this due to borrowing or loan translation? (Campbell notes that French tête was borrowed from Italian testa, but there's also German and Dutch).
Pipil (Uto-Aztecan) tsuntekumat 'head' comes from tsun- 'top, hair (in compound words only)' + tekumat 'bottle gourd', and has replaced Proto-Nahua *kwayi- for 'head'.Not a drinking tool, but maybe there are head-shaped bottle gourds? – Jan 10 '12 at 14:21