If you're like a lot of people, you've run into someone on the internet who lied about who they are. I know, shocking, right? We all know it happens, but we also like to believe that we're smart enough to figure these people out... until someone manages to fool us and we end up feeling silly and stupid.
Of course. the easy solution is to become hardened and cynical, but that doesn't feel especially fair or healthy. No, what we want is to nurture that remaining sliver of childlike naivete while not getting completely ripped off.
Follow me below the curlicue and we'll get that radar humming!
The most important thing to remember about liars and the lies they tell is that they're like sperm - they're genetically designed to reach the target. No matter how good your defenses are, sooner or later, someone is going to lie to you successfully. Don't feel bad about it; it's a natural byproduct of living in a group. You either learn to deal with it or move into a cave. I suggest the former because caves usually smell bad and the moisture plays havoc with computers and whatnot.
Rule Number 1: Bell Curves, People!
While we are all unique, we are not all extraordinary. Most of us are limited to one or two areas of coolness, with everything else being fairly mundane. One of the easiest signs of a liar is that they are special in too many ways, especially if those things are unrelated.
Now, obviously if I tell you that I'm sleeping with a supermodel in between winning speedboat races and chess tournaments as a grandmaster, you're going to be suspicious, as well you should be. On the other hand, if I tell you that I have a graphical/spacial memory that allows me to be able to draw a floor plan of every building I have ever been in, do I set off alarms? Probably not.
That's because that special gimmick doesn't convey social status. People are much less likely to lie about things that don't earn them special approval. I mean, when was the last time someone lied about having a double-jointed toe?
Rule Number 2: Follow the Agenda
You know how in almost every detective drama, someone says, "follow the money"? When it comes to detecting lies, it's very helpful to consider what the speaker hopes to achieve with their tale. This is their agenda. Every conversation has a purpose, even if it's alleviating loneliness by communing with other people for a while.
Not every agenda is sinister. When you go to the dealership, the salesman wants you to buy a car. The trick is to look for the hidden objectives. One of the most common of these is to isolate or marginalize someone who disbelieves the speaker. We're going to come back to this in a second.
Rule Number 3: Pedal to the Metal
Liars commonly seek to accelerate the process of developing trust. If you feel like you're being asked to give more of yourself than you normally would at this point in a relationship, you have cause to worry. Liars push this because they know the odds - the longer it takes you to invest in the con, the more likely you are to see through them. They know, often subconsciously, that it takes a great deal of effort to overcome trust once you've established it.
Once common shortcut is a logic error. They offer you up one thing as proof that they are trustworthy and then effectively say, "If I didn't lie about X, I couldn't possibly be lying about Y!" Be wary of people who make a point of establishing facts that shouldn't really be in question or who go out of their way to prove their trustworthiness.
Rule Number 4: You and Me Against the World
Another method of artificially accelerating a relationship is to designate a bad guy. This touches back on Rule #2 in that liars really like to project onto people who might interfere with their goals. Sometimes this is overt - "I think he might be your stalker" - sometimes it's more subtle.
Liars know that getting you to defend them is the sort of emotional investment that gets you stuck in the web. It's all the better if they can get you to defend them against someone that might actually expose them.
Rule Number 5: Chaos Abounds!
Much of our lives is actually fairly routine. We make a big deal out of events like marriages and births because they mark a change in the everyday. One of the best signs of a liar is that weird stuff is always happening to them and it's never their fault. If you pay attention, most of the chaos serves to obligate others to take care of them codependently. What you should be looking out for is anything that encourages you to intervene.
Another possible cause of artificial chaos is that it moves the liar to the center of attention without requiring them to resort to the riskier deceits. Remember, the goal of the liar is to get you to do/feel what they want without you feeling bad about it or catching them. Liars know that simple lies are almost always better than complex stories. If worse comes to worst, a simple lie can possibly be framed as a misunderstanding, while a complex lie can be genuinely debunked.
Rule Number 6: House was Right
Everyone lies. Everyone.
(Please, for the love of God, don't fill the comments with nonsense about how you've never told a lie. Every time you've shaded a response or left something out, you've avoided the truth. It's in the nature of people, deal with it.)
Once you accept that, you're going to have to determine for yourself what you will and will not accept. My only advice in that area is that you consider the intent of the lie and the context that led to it.
EDIT:
Rule Number 7: An Important Thing that Michael Forgot:
Contextual embedding. We've talked about how liars prefer simple lies because they're easier to remember and maintain, but often liars lack the forethought to add dimension to a lie. This is especially true of significant events and achievements.
Take me, for example. If we're talking about our experiences, I could just tell you that I went to Florida a couple of times as a child. That doesn't help you very much. If you draw me out, however, I would probably tell you that my least favorite memory of those trips was how everything smelled funky after the 15-minute downpours they seemed to have every afternoon and how I didn't really care for either Disneyland/World/Whatever or Epcot center until we were about to leave and noticed some really cool fountains that shot high pressure "slugs" of water. I might also tell you how that's where my aunt and uncle live now and, seeing as how I don't really like him all that much, I'm unlikely to go back.
Now, the good thing is that this sort of detail can verify a story. The bad thing is that a skilled liar will prepare these. They can also be used as tools to create that artificial intimacy liars work toward.
The easiest way to trip someone up on contextual embedding is to take the conversation in an unexpected direction. You could, for example, ask me about the food I ate while in Florida. My answer isn't as important as my reaction to the question and how I appear to retrieve the information. Every place we go and every thing we do leaves a mark on us. The trick to separating real experiences from false is getting them to reconnect with the emotions of that experience.