Asking why a wink means flirtation is pretty much a question without an answer. You might as well ask why a shrug means “I don’t know”, or why “I don’t know” means what it does. Gestures are an adjunct to language and evolved way back in the mists of time.
Mind you, just as everybody doesn’t speak the same language, so too do gestures mean different things in different places. In North America, if you make the “Okay” sign (making a ring with your thumb and forefinger), everybody knows what it means. But in France it means almost the opposite; it means “Zero” or “No good”. I also seem to recall that in Italy it means something obscene, since the circle represents part of the female anatomy.
Why don’t you try searching for “gestures” on an internet search engine? Maybe they’ll give some alternative meanings for winking.
Come to think of it, a wink doesn’t always mean flirtation. Sometimes it means, “I’m not being serious”. And let us not forget the old “Wink, wink, nudge, nudge” of Monty Python fame.
On a side note, I’ve heard that the shrug gesture came into existence around the time of the French Revolution. It was an allusion to the Guillotine. Originally a gesture that meant something like “I don’t want to tell you, because I’m afraid I’ll get my head chopped off”, it somehow became “I don’t know”.
I could be completely pulling this outta my ass though, so please someone tell me you’ve heard the same etymology?
After careful consideration, I’ve devised an experiment.
1)Go to local bar.
2)Drink 13 beers in rapid succession.
3)Find mirror.
4)Try to blink; if both eyelids close, repeat step 2. If only one eyelid closes, proceed.
5)Find someone of the opposite sex (or the same sex, whichever dots your I’s) and repeat step 4.
6)Observe results.
I feel these conditions faithfully replicate those under which the vast majority of flirting occurs. Please post your results.