He's calling the training and abilities of such people into question. And I think it's a legitimate concern. Have we performed any studies on such behaviorists

He's calling the training and abilities of such people into question. And I think it's a legitimate concern. Have we performed any studies on such behaviorists to determine if they are better than people with no training? Are they succumbing to personal prejudice? (That's where race comes in.) How do we even evaluate such things? Schneier has written favorably about the Israeli approach (https://www.schneier.com/blog/archives/2005/07/profiling.html https://www.schneier.com/blog/archives/2005/07/profiling.htm...) while more recently has pointed to research which calls the UK and US approach into question (https://www.schneier.com/blog/archives/2010/06/behavioral_prof_3.html https://www.schneier.com/blog/archives/2010/06/behavioral_pr...). Schneier's take is that the Israeli approach does not scale to the US (https://www.schneier.com/blog/archives/2010/01/adopting_the_is.html https://www.schneier.com/blog/archives/2010/01/adopting_the_...). If I understand his point, it's not so much the training of looking for behaviors, but the amount of time spent with each person. I am personally skeptical that anyone can be trained to identify behaviors indicative of terrorist activity, and that such a person would not just succumb to their own personal biases.