LIVING OUR LIMBIC LEGACY 47behavior is to watch people who put one or both arms under the table. If
they are doing leg cleansing, you will normally see the upper arm and
shoulder moving in conjunction with the hand as it rubs along their leg.
In my experience, I find the leg cleanser to be very significant because
it occurs so quickly in reaction to a negative event. I have observed this ac-
tion for years in cases when suspects are presented with damning evidence,
such as pictures of a crime scene with which they are already familiar
(guilty knowledge). This cleansing/pacifying behavior accomplishes two
things at once. It dries sweaty palms and pacifies through tactile stroking.
You can also see it when a seated couple is bothered or interrupted by an
unwelcome intruder, or when someone is struggling to remember a name.
In police work, watch for the hand/leg pacifiers to appear when the
interview session starts, and then note if they progressively increase when
difficult questions arise. An increase in either the number or vigor of leg
cleansers is a very good indicator that a question has caused some sort of
discomfort for the person, either because he has guilty knowledge, is ly-
ing, or because you are getting close to something he does not want to
discuss (see box 12). The behavior might also occur because the inter-
viewee is distressed over what he is required to answer in response to our
questions. So, keep an eye on what goes on under the table by monitor-
ing the movement of the arms. You will be surprised at how much you
can glean from these behaviors.
Heed this cautionary note about leg cleansing. While it is certainly
seen in people who are being deceptive, I have also observed it in inno-
cent individuals who are merely nervous, so be careful not to jump to
any conclusions too quickly (Frank et al., 2006, 248–249). The best way
to interpret a leg cleanser is to recognize that it reflects the brain’s need
to pacify and, therefore, the reasons for the individual’s behavior should
be investigated further.
The VentilatorThis behavior involves a person (usually a male) putting his fingers be-
tween his shirt collar and neck and pulling the fabric away from his skin