"Perhaps it is
useful to consider one of the strangest displays
that can be seen in many different mammalian
species &endash; "yawning". The purpose of
yawning has been the subject of intense
speculation by a small group of scientists and I
receive monthly e-mail bulletins from a
French-based society dedicated to this subject
(www.baillement.com). This is indeed a curious
behavioural display and is a beautiful example
of an involuntary expression that is pleasurable
and that we, as humans, use voluntarily to
deliberately communicate boredom. It is also
highly infectious with yawning, perhaps even
more than smiling, being likely to induce the
same display in others that see you doing it.
Recent brain imaging studies have even suggested
that observed activation in the temporal lobe
during perception of yawning may actually be
directly triggering "imitation" of this
behaviour."
