Whether or not it works is only part of the issue.  I was really angry when I first heard about this, back in August, and sent the TSA a complaint.  I'm sure I'm on a list now.  Their response has some handy contact info, but is otherwise completely useless:

Thank you for your e-mail message.

So that we can better assist you we encourage you to call us at 1-866-289-9673 for assistance.  If you are outside the United States and cannot use the toll-number, please call us at 1-571-227-2900.  

We hope this information is helpful.

TSA Contact Center

Uh...not very helpful, no.

care about individuals, or about reason.  They always claim that what they do is "within policy guidlines", regadless of the outcome.  Just following orders.

not TSA.  Not that it makes it right, but she was showing far more than subtle cues.

looking for a no-bid government contract to help fight the GWOT.

Lord knows, they would have hauled me away a few dozen times for that momentary "flash of anger" tell.

Like the time I was going through security and my bag was opened after going through the X-ray thingy and one of TSA's finest triumphantly rooted around and pulled out my toothpaste.

I had, what originally had started out as a standard tube of toothpaste and now, after a period of usage at home consisted of a tube containing about enough squeezes of dentifrice to get me through a four day trip - or so I thought.....all told, well under an oz.

But, that was no defense for TSA which informed me that the TUBE itself, when fully loaded, had a capacity to hold more than the allowed 3 ounces of product.  Never mind that there was nowhere near 3 ounces actually IN the tube.....just that it COULD hold more than 3 oz. IF I could somehow locate 3+ ounces of C4 or primer cord or dynamite or whatever inside security.

I was then asked if I would like to take my entire bag and go back to airline check-in.....check the bag through and retrieve my ounce of paste and the bag at my destination.  Or, they could confiscate the dangerous dentifrice to save me and the free world from a Colgate conflagration.

I seethingly flashed my telltale anger by replying, "Do I look like I got Stupid tatooed on my forehead? and then advised them that having already spent 20 minutes in line just to reach their location, taken off my jacket, belt and shoes, my cell phone, and pen, put the two computers I was carrying in their own trays, and emptied my pockets, I would forgoe that pleasure and that they could therefore keep the damned tube and put it in the museum they must have which let them display yet another example of how they had made the world safe once more for truth, justice and the American way.  They did not seem to find that amusing....nor did I.

Oh By the Way....in thinking about how these procedures make us all safe....remember that about 17-20% of the fake weaponry which security system testers try to slip through -- is NOT found by TSA.  There....don't you feel safer now?

I am:

(1) Questioning if it is legal.

(2) The people doing it have the training and experience required.

From the article linked in my post:

Blas-Bamba and her team were trained in fall 2006. She says she did behavioral detection of a sort in her last job as a probation officer. "We all do it to a degree. It's just a matter of understanding and articulating what we see."

local fuzz last year for DIU.......he thought he was on the cutting edge of CSI type deductive science. Only problem was, I was clean and sober, but only tired. He was very surprised when I blew 0.00 BAC and gave a clean drug free urine.

Microexpressions may work in the lab and with educated professionals, but in the hands of a bunch of high school drop-outs, I fear more mischief than solid, useful results.

Did they have a brief flash of fear?  
Or were they too exhilerated?

This is designed to catch up average citizens who may have made a mistake, been confused, don't know the answer to a pop question, have physical problems or are, god forbid, just plain jet-lagged after an 18 hour trans-con flight, with attendant layovers.

The results even in the Scientific American article run counter to practical experience with trained police who have used these techniques. Again they are wrong as often as they are right. No matter how much the police believe that they can find a liar.

Also the people who are least likely to be caught are  in order; trained intelligence agents, trained terrorists and sociopaths. The people most likely to be caught are great-grandmom and great-grandad with an undeclared prescription drug. Added to this is that the studies cited in SciAm are preliminary at best, deal with an isolated subculture in white America and you have catchy but bad science at its worst.

Some people have no problem with being pulled over for second round interviews or third round interviews or interrogations, but it irks the hell out of me and is just another sign of our slipping further and further into a police state. Those that think that this would have prevented 9/11 are out of their minds. We already had the technology to catch the terrorists before the fact back then - we caught them on video. The real problem was that we had incompetent people from the top to bottom of our government who were asleep at the switch.