Why is lying on my mind this week? Two words: Alex Rodriguez.

I was in Miami last Saturday evening when I returned to my hotel room to change for dinner. Suddenly, there as the top news story of the CBS Evening News was the report that A-Rod had tested positive for steroids during the 2003 baseball season - along with a video clip from the third baseman's interview with Katie Couric on 60 Minutes in 2007.

"I've never felt overmatched on the baseball field," A-Rod said, in response to Couric's question about whether the potential future Hall of Fame slugger had ever used performance-enhancing substances. Then he added, "I've always been (in) a very strong, dominant position...I didn't have a problem competing at any level. So, no."

But that was only the end of A-Rod's verbal response to the question. Immediately afterwards, he smirked - a sign of contempt, with the left corner of his mouth rising up and out, forming the kind of tight "pocket tornado" that portrays a lack of respect.

I'm a facial coder, just like the star of Lie to Me. And in fact the person who's the inspiration for Lie to Me, Dr. Paul Ekman, is the person I learned from in getting my start in this field. Now, reading the facial muscle activity of others to detect their emotions isn't an open and shut case. Ekman's system involves 23 different combinations of muscle movements that correspond, in turn, to seven core emotions that go across cultures. Most of the movements can fit more than one emotion.

But that's not true of smirks. They have a single meaning: contempt.

And the moment I saw A-Rod's smirk, I turned to my wife in the hotel room and said: "He's lying." To me, what A-Rod was showing was a dismissal - a distancing - of himself, emotionally, from his own answer. So it was no surprise to me when he confessed shortly thereafter to using steroids.

After all, I'd seen a similar sign of disbelief in one's own answer when Paris Hilton's upper lip had curled upwards in a sign of disgust when she dutifully told Larry King that, having gotten out of jail, she would now transform herself into a "good girl."

Contempt and disgust are, in emotional terms, like first cousins. Really, the primary difference is that contempt is a bit more contemplative, with a moral judgment aspect to it. Disgust is more visceral in its rejection of something or somebody.

Roger Clemens is also, I believe, lying about his record in regards to steroids use. Over time, the truth will come out. But if the truth is that, yes, he used steroids, I won't be surprised. For in Roger's case, the telltale sign I saw from the hurler's testimony before Congress and in the hallways of Congress is that when the question was specific enough, a ballplayer known for his fearlessness on the mound exhibited plenty of , with his lips pulling wide.

The reasons why people lie are as varied as the ways in which they betray their true feelings and the likely disconnect between words and emotions. Everyone likes differently. The motives for lying likewise vary. A-Rod and Clemens have all the money they need. So in their cases, we're on to something else: legacy. Both want to be remembered as great players, not as poor liars. In Emotionomics terms, it's hard to put too high of a price tag on pride.