Grant, your link to the article doesn't work. Get your eight fingers and two thumbs working to fix it!
Thanks! Dunno what happened there.
There are some funny and odd responses on that survey, as one would expect! The dictionaries I use seem to cop-out a bit on the issue. For example: “One of the five digits of the hand, especially one other than the thumb.†Especially?
Interestingly, in France, when counting with fingers, they begin with the thumb for number one, rather than the index finger as we Americans do. But that doesn't really point the evidence one way or the other, so to speak. It's hard to put a finger on an answer that everyone would give a thumbs up to.
That's not a cop-out at all--it's accurate reportage. In most cases, there's no reason not to consider a thumb to be just one of the ten fingers, but it's true that sometimes the word is used that way. It's not something to which there's a right or wrong answer, just a question of usage.