The recent research has expanded in two directions. The list of easily recognized facial expressions has been lengthened and the research of cerebral hemispheric specialization has spun off investigations of asymmetrical facial expression. Perhaps, the most intriguing concept revealed by these two branches of research is that human facial expressions involve not just two areas of the face, eyes and mouth, but rather four areas; the left and right hemifaces, which each can be divided into the eye and mouth areas.
Of course, communication involves, at least, two people, so that analysis of nonverbal communication, in the form of facial expressions, requires observations and explanations for changes in eight facial areas.
Needless to say, the expansion the list of research verified recognizable facial expressions could be a never-ending process. There are hundreds of words used to describe human nonverbal behavior and many of them have corresponding facial expressions. Words such as concern, affectionate, antagonistic, domineering, submissive and passive will undoubtedly be linked to particular configurations of facial muscles, at some point of time.
The research into the difference of facial expressions displayed on the right and the left hemifaces has uncovered an interesting relationship. The right hemiface displays expressions associated with approach behaviors (Extroversion?), while the left hemiface displays expressions associated with withdrawal behaviors (Introversion?) (Davidson, Saron, Senulis Ekman, & Friesen, 2006). It almost seems as if the mechanism responsible for the flight or fight response is also responsible to some degree for hemifacial orientations.
It has been known for some time that the right hemisphere of the brain is the hemisphere where most emotional processing occurs (Feeling?), while the left hemisphere processes most verbal and language information (Thinking?) (Root, Kinsbourne & Wong, 2006). Verbal abilities might develop from the nonverbal approach, as, perhaps, the neurological structure that causes this hemifacial distinction is also responsible for verbal behavior as language can be seen as ‘remote’ approach behavior. Research dealing with the facial expression of infants supports this hypothesis. Adult facial expressions are more apparent on the left hemiface, because in the mature brain the right cerebral hemisphere processes emotional data.
A pleasant exception from the not-so-cute pommy backpacker girls I'm used to seeing in Oz :/ 
