In what language do deaf people think?

Wow that is mind-blowing. I could not possibly imagine a world without words, especially the ones in my head. It goes against every intuition I have to believe in thought that lacks language.

Really? I'm bilingual from childhood (and I've since learned a few more), and I seldom feel like I'm thinking in any specific language. Furthermore, I don't see how that could be puzzling to anyone - haven't most people had the experience of temporarily forgetting the word for something that they are very familiar with? A situation where they have a concept in mind, but have forgotten the "label" for it in their language? So why couldn't people think using these wordless concepts instead of with words?

(To me, thinking in words seems strange and inefficient. On the other hand, I often have clear and simple thoughts in my head that take me several minutes to translate into any language, because none of the words and expressions I can think of seem just right, so thinking in words seems like it would be useful for communicating.)

People think in different ways. I almost never think in "words" because I'm a visual thinker, but my girlfriend absolutely never grasps for a word. I assume the deaf have differences between language based thinker and visual thinkers or kinetic thinkers.

For my part I know that I don't strictly think in words, or pictures, or any other such representations. I'm sharply aware of this because I'm relatively slow putting thoughts into words; so when I have some thought, I can consciously hold that thought in my head for a moment before the corresponding words come to mind.

For instance, suppose I realize I'm out of milk. It'll come to mind that I should go to a grocery this afternoon to buy more milk, but this intention doesn't form as a complete sentence in my head. It may literally take a couple seconds for me to recall the vocabulary I'll need to express this thought in words, but I can continue thinking about my trip to the grocery -- which one I should go to, what else I need to pick up there, etc. -- before any words have even come to my mind. So ideas and their linguistic representations are very distinct to me, and sometimes I don't even bother with the latter at all, because (for whatever reason) forming the linguistic representation of a though imposes a significant overhead on my brain. (I'm also dyslexic, for what it's worth, and I often wonder of these issues are related.)

My hypothesis is that for people with better functioning language centers than mine, words may come to mind so easily that the delay between thought and linguistic representation is imperceptible to them, hence they "think in words". But for people like me those words might come late or not at all, but regardless, I do think all the same...

Communities evolve language spontaneously. Evidence of this is a school of deaf children (in Brazil IIRC) who were not taught sign language (due to lack of a teacher, due to budget). They developed their own, which became quite complex and of comparable sophistication to other human languages.

Taken with the conclusion of the submission that abstract thought requires language for its development, this leads us to the conclusion that abstract thought - far from an isolated activity - is a consequence of community.

It seems to me that it would be possible to develop abstract thought in isolation, but perhaps it would take a genius, in the same way that some mathematicians have developed mathematics in isolation, and it's just that it helps tremendously to have the cultural foundation to stand on. eg. I find it much easier to visualize abstraction, reference and so on, than to say it.