A new study conducted informally by me by observing people shows that nobody knows how to flirt.
Men don't know how to do it. Women don't know how to do it.
This is the source of the great divide [when there is one] between the sexual side of the [a] person and the simple-social side, as flirtation is the bridge.
I suppose flirtation doesn't happen as often even among people between whom it would be apt because they're not serious to any degree and they feel like they'd just be being a tease to flirt and not follow up [with more, like, commitment-y, on-off binary relationship-y stuff], so, wanting to be nice people and seeing flirtation without [such] follow-through as rude, they abstain from flirtation in the first place.
Worsening the divide are the loose freaks who are in opposition to the stance that people who [just] want to get along well in society hold. I'm talking about the "loose" people: manwhores and pairs to [of] women that troll together for three-ways with strange men, and such and the like. Noting these freaks' "flirtations", the good people of society don't want to do anything that could make others confuse them with those freaks, so the chasm has a fence erected around it.
Really, the "flirtations" of such people are to flirtation as methamphetamine is to dopamine. It may simulate it and be indistinguishable [from it] without analysis [(according to the brain, in the case of meth)] but it is fundamentally a different thing. Back in metaphor-land, the manwhores and ubersluts are launching themselves across the chasm in a freaking CANNON. It gets them across, but it is fundamentally different from the bridge that genuine [actual] flirtation is.
While these cannonballs fly across, people forget about bridges and simply resign themselves to these drastic measures and an unscientific, gambling style of finding their way to the other side each time.
Only the [archetypical] massive failures ever get [have gotten] popularized, and those who've never been exposed to realm of flirtation at all [only] get a view of it as [being] mostly made of [instances of] guys being retards, women hurting others' feelings [in wholesale-ly rejecting them], and of random pairs of men and women meeting [each other], being in friggin' love immediately, and each seeking the other from Millisecond One. With only so polarized a set of representations [available to most people], the [that] highly multi-shaded [portion of the real] world that falls in [is] the realm of flirtation is left with its subtle darks and lights of grey indistinguishable from each other to those 'most people' without loads of practice.
Flirtation is not something that you can 'jump' straight into [at all]. Flirtation is something indistinguishable from normal conversation at a distance or at low levels. It will start as an interaction that can go anywhere,--to flirtation etc., to a fight, to a business arrangement, or anywhere else--and then the character of the interaction may get changed by changes in the content which happen in ways that may be sudden yet subtle, subtle yet sudden, or somewhere in between. The misconception of flirtation being like a pool where you can just jump in--[having a distinct, switch-like, on-off state]--has hurt a lot of people and opportunities.
[Editted, uglified, and sensible-ized on 19Mar2010]