I have the BEST gaydar.
Whenever I meet a man, my brain runs through a sophisticated algorithm to determine the JayQueer-certified %homo index of a man.
The algorithm includes running through the following assessements --
-- The voice of the man (how deep is the voice, the inflection -- most gay men have a "lilt" to their voice)
-- How they speak (a lot of gay men, especially more effeminate gay men, end sentences with leading phrases, which is a sign of more insecurity/lack of confidence. Straight men tend to speak in shorter sentences, more to the point)
-- Body posture and body language* (American gay effeminate men tend to be more expressive with their hand gestures and tend to stand with their legs close together, or mimic more feminine or subdued body language. American straight men are more likely to stand shoulders wide apart, legs wide apart)
-- Career (What job does he do? Is he an engineer (more straight) or an interior decorator (more "gay")?
-- Hobbies (What are his hobbies? Does he like to go to drag races (straight) or drag show (gay)?)
-- TV shows & movies (Does he watch soap operas, & Bravo, or ESPN and the NFL?)
-- Interest in Sports?
-- Political affiliation? -- Statistically, if he is a Democrat, he is more likely to be gay, if he is Republican, more likely to be straight
-- Personal grooming (Does he look unkempt, well-groomed, or overly groomed with shiny makeup?)
-- Clues to relationships (Is he wearing a wedding ring?)
Based on the above criteria, plus other factors, I put together a %homo index.
Here is the scale:
0-25% -- Straight man
26-50% -- Straight man with bisexual tendencies/ Metrosexual
51-65% -- Bisexual man/ Metrosexual/ or Very Masculine Gay Man
66-75% -- Masculine Gay Man
76-85% -- Typical Gay Man
86-100% -- "Flaming" or "Fabulous" Gay Man
hahahaha, this is so true---my Gaydar does a complex yet quick analysis of the guy/situation too (and I am usually 90% correct, which I think is damn good)....although I don't 100% agree with the homo-index scale, I think you sorta hit the nail on the head.
I want to append:
-Lots of gay men have a lisp
-They are likely to not just go ahead end the or phrase or sentence, instead they feel the need to be "extra" and keep it trailing (i.e. "oooooohhh my Gooooooooood" or "I just went to Express and got a deal that was just too good to be truuuuuuue", instead of just "oh my God" or "...too good to be true"
-I agree with the hand gestures and female-insprired postures/poses. Gay men tend to express everything with their hands (not in the masculine sense, but in a feminine sense)
-Career and upkeep/grooming are questionable. I have seen gay people as engineers or IT techs, but you tend to be right...gay people tend to choose jobs that are "cute" or not physically demaning or that won't "get them dirty", such as hairstylist, interior design/art/fashion design, call center, receptionist, marketing, or communications. Regarding grooming, I have seen some dirty, grimy gay/bi men (lol). In contrast, I have seen some very well-dressed straight men---at my gym recently, I saw a straight guy with a manicure and he was wearing a Burberry shirt and Ferragamo shoes with Versace boxer briefs; I was quite shocked at how well-dressed he was for a straight man.
I also want to add:
-eye contact (if he looks you up and down, or tries to discreetly look at your bulge, or does a double-take)
-the twist of his hips (let's admit, most gay guys have a feminine walk)
-the car he drives (although I have seen some gay guys drive large sedans or trucks, many choose to buy a "cute/petite" vehicle like a VW Bug or a Corolla or a Civic or a Focus)
-also just observe the content of his conversation when he speaks confortably and freely (if every two seconds he is talking about what "fabulous" trip he went on or what establishment he dined in or what he bought on his last shopping trip or if he refers to interest in a play/opera/museum exhibit/theatrical production/Broadway musical/etc)
-pay attention to his vocabulary (excessive use of female-inspired words or the words "soooo" [as in "OMG, girl, I am soooo stuffed"] or "fabulous" or "OMG" or "whatever" or "hey you" or "as if"
-referring to themselves/their friends as the opposite sex (e.g. "I'm a diva" or "Bitch where you been" or "Girl, I got something to tell you about that guy I fucked last night" or "You will never see anyone as beautiful as me" or "I gotta go to the gym to work on my ass and hips so I can fit my Forever 21 jeans" or "Can you give me a short cut & make me look pretty like Demi Moore or Rihanna?")---->saying this to the hair stylist....lol
-one more....if he has MANY female friends and/or if his "BEST FRIEND since 5th grade" is a female, or if he has female roommate(s)---then that is usually a sign that he is gay (straight girls usually feel comfortable living with gay guys because they don't feel sexually threatened & look at gays as "one of them"), or at the very least bi
These are just MY observations, I am in no way saying these hints are written in stone...I am simply answering the OP's question from my point of view.