Michael Vassar of Overcoming Bias has a good explanation of why people often brand Nerds and upright men as liars and hypocrites: “Some commentators proposed that “Nice guys” feel entitled to sex, and are liars. Why? Suppose that middle-class American men are told, at an age too immature to examine parental commands critically: “In dealing with women, be X, Y, and Z” where X, Y, and Z are instructions like “Only express sexual interest in those women who you are confident are interested in you, prior to that, always be polite.” And middle class American women are told, in a similar fashion, “In choosing a man, look for politeness and respectful non-sexual behavior.” But when women grow up, they find that they aren’t attracted to the men they were told to look for. Maybe they believe, with reason even, that such men are ‘boys’, not ‘men’, and find this unattractive (ultimately because it was and still is evolutionarily unfit). Instead, most women spurn the timid advances made by the ‘nice guys’ they think they should prefer. But since they believe they should be choosing such men, they also decide that the men they reject cannot be the type they were told to prefer. This may explain why ‘nice guys’ might end up labeled ‘liars’. Nerds tend to be literal, to lie infrequently, to greatly resent being lied to, and to not adjust their behavior based on information their brains have not yet verbalized. Nerds are also reluctant to behave hypocritically, e.g. by verbally condemning a behavior while engaging in said behavior. If this is what is socially demanded of them, they will be unhappy with the situation.”
LessWrong too has an interesting bit on such dishonesty: Steven Pinker has an excellent chapter on this in “The Stuff of Thought”. While there are several reasons we lie, the most important reason is to avoid mutual knowledge: “She probably knows I just blew a pass at her, but does she know I know she knows? Does she know I know she knows I know she knows?” Etc. Mutual knowledge is that nightmare where, for all intents and purposes, the known-knows can be extended out to infinity. The ultimate example of this has to be the joke “No, it wasn’t awkward until you said, ‘well, this is awkward.'” A situation might be a little awkward, but what’s really awkward is mutual knowledge, created when someone blurts out what’s going on for all to hear.
Mencken had a pretty sound observation too: “If, indeed, any individual among them shows an unusual rectitude, and refuses spectacularly to take what might be his for the grabbing, Homo boobiens sets him down as either a liar or an idiot, and refuses to admire him.”