I think it helps a lot to pick up the non verbal cues a person is giving off and a lot of us do it naturally. However, I've always been put off by the "lying eyes" teaching. My eyes almost always naturally shift to the right when I am thinking because my left eyebrow typically also goes up. (I've done it for so long that eyebrow is actually slightly higher than the other). I just tried looking up and to the left with my left eyebrow arched and it feels weird. So weird. :-)