As I get older (read more experienced socially) I have gotten a lot better in determining whether someone is a winner or a loser. Without knowing how much they make, how well they get along with their families, how in order they have their lives, I can usually tell in the course of a conversation whether the person is basically a winner or a loser.

So how can you tell? Here's some things I look for:

A Winner…

1. Leaves a given situation better than they found it. If you loan them something or let them use something of yours, you'll get it back in as good or typically better condition than when you loaned it.
2. Never takes advantage of the good will of others. Winners see the good will of others as a gift to be honored and will respect it.
3. Takes responsibility for failure without making excuses. If something goes wrong, they cut to the chase and will say "I blew it, it's my fault I will make it better."
4. Takes the long view of things. Winners are very good at looking at things from the long term. One of the reasons why winners tend to have money is because of this trait.
5. Has a strong sense of delayed gratification. Winners can control their short term desires in order to build a better future. For instance, proving that money isn't what separates a winner from a loser, a winner's home will almost always be bigger and have nicer things in it even if they make the same amount of money as their loser friend because the loser will have squandered their money on junk.
6. Sees themselves as masters of their own destiny. Winners are captains of their own lives. Whether they are poor or disabled, they will still see themselves as being in control.
7. Tries to learn how successful people became successful. Winners learn to recognize other winners and see what they can learn from them.
8. Knows life ain't fair and deals with it. Winners know that life is indifferent and random. They will adjust their course based on the obstacles put in their way.

A Loser…

1. Tends to leave a given situation worse than they found it. Ever loan someone a car or let someone borrow one of your things or stay at your house? The quickest way of seeing if someone is a loser is if they trash your stuff. Loan a loser a car and it'll come back with a stain on it. Loan them a tool and it'll come back broken. Let them stay at your place and they'll leave it a mess.
2. Will exploit the good will of others. Losers are fundamentally inconsiderate and this is a big reason to what dooms them to being a loser. "Success has many fathers" is true in so many ways. To be successful you need people to help you and losers will always ensure that people aren't helping them because they will squander the good will of others before they can get very far.
3. Makes excuses for every set back and blames others for failure. Another easy way to spot a loser is the plethora of excuses they give. Nothing is ever their fault. You can even get an idea to what degree of loser the person is by how ridiculous their excuses are. The greater the length the person goes to avoid taking responsibility the bigger the loser.
4. Thinks only of the here and now with little thought of the future. Losers always seem to lack any foresight. They'll do things that have inevitable severe consequences and yet be oblivious to those consequences because they can't think more than a few days ahead.
5. Has to have things now. One of the reasons why losers never seem to have money is that they have no self-control. A loser won't have any sort of investments or savings but will have an Xbox 360, Play Station 3, and a Wii and then bitch about not having any money. Losers seem to consume toys and junk like others breath air. As a result, they never build any sort of assets.
6. Sees themselves as victims or having "bad luck". Nothing screams "loser" louder than someone saying how some authority figure "had it out for them." Please. While there are certainly bad actors out there, nearly always it's just a loser trying to argue how they just got screwed rather than recognizing that maybe they should have done what they were supposed to be. "Oh, she had it out for me, she was just waiting for me to show up twice in a row stoned so that she could fire me!"
7. Thinks successful people were just lucky. Losers have envy down pat. It rarely if ever crosses a loser's mind that they might learn something from winners. That's because they think winners are just lucky. A loser is good at finding a minor obstacle and using it as an excuse to fail. "Oh, if only I could sing, then I could be a rock star and be rich! If I could sing then I wouldn't be living in this dump." Life is a bit like a race in the sense that from the end of high school on you see increasing differences between the different people in terms of lifestyles. Some people certainly get head starts because of mom or dad helping them. But over time, life has a way of sorting things out quite a bit. If you've become successful in some way, the differences between you and others may be quite significant. So when if you run into a contemporary, you can usually tell without asking about their background if they're a loser by how they react. If they behave enviously or use the term "luck" several times then odds are they're a loser. In the few times where I have inquired about what they're up to, sure enough, they're a twice-divorced, semi-dead beat dad working at some crappy job in which their boss is "screwing them over" living in a crappy apartment (but with a state of the art cell phone and Playstation 3 of course).
8. Worries about what is "fair". Nothing is more annoying than people who think there is some sort of objective "fairness" to life. Here's a quick way to know if you (the reader) are a loser or a winner: Are you making enough money where you currently work? If you feel you're underpaid, then a winner will work harder to show demonsratable results and failing to get appreciation for their hard work will find another job. A loser, by contrast, will rationalize working less and screwing off more at their job because they're not paid well enough (which due to #4 means they'll always be a low paid drone because they don't recognize the logical consequences of that strategy).

What's amazing is how easy it is to spot winners and losers. It's usually incredibly obvious within moments of meeting someone. Most people aren't losers. But it's not a gradient or anything like that. Those people who fall into the loser category tend to be full-hog into that category (i.e. meets almost all the criteria in a big way). That's what always shocks me is that losers don't just have one or two of these traits, they almost always have all of them.

As an employer, I've employed my share of losers (I'm getting better in the interview process). I've seen people who have had every opportunity completely squander our good will and blindingly sabotage their own futures through an amazing lack of foresight, victim-role playing and lack of self control.