I have a bachelors in psychology with a minor in philosophy and I can tell you that sometimes it is disregard for respect, but also sometimes lying is just as much an addiction as drugs are. Sometimes people honestly can not help it, for absolutely no reason they will just blurt out a lie and when asked why they will tell you that it slipped, its not premeditated, they dont mean to harm others but that they just cant stop it. Its honestly a problem.
But as well when its someone that you know and care about thats lying to get some sort of gain, such as someone that lies about cheating, in order to gain or keep your trust. That is different.
People that lie about mundane, often silly things will most often confess that they just dont know why they do it.
But anyone who says they loathe and despise liars I have to question that they might be a bit hypocritical, from the time that we are young we are taught that sometimes lying isnt just acceptable, its the right thing to do. We have all lied.
No one likes to be lied to, and at the same time, no one likes to be wrapped in a web full of lies. When you find someone lying to you that you care about, the worst thing you could possibly do is rudely rip them off of their feet and make them lose any bit of self confidence they might have. If you care about that persons friendship you need to talk to them and ask them why they felt it was necessary to lie to you. They will either say that 1) they just didnt mean it, it just happened. or 2) that they lied because they were scared of your reaction to the truth.
Same here, I've end a lot of friendship with people who I thought were my friends, and pretty much they all are aware that I cannot stand liars, and some of them were caught with their pants down with a bunch of lies they've told, Now you see why they are no longer my friends? Once a liar would always be a liar, that's what I believe. 
do they talk with you anymore 
I am a big liar!!! 
