The first movie is a Quicktime movie of a female Head-Toss. The second movie shows the difference pictures. This can be done for different body regions in different persons. The result is a continous data-stream which can be plotted . The results are discussed in terms of assymmetric investment in the offspring.
Females try to elicit information from the male, without disclosing their intentions.
This happens under the pressure of possible deception of philandering males, which becomes more likely when the male recognizes the intentions of the female. Other results indicate that human non-verbal behaviour is highly structured and rythmic. This is clearly demonstrated by the analysis of a two-minute interaction between a male and a female. Movements are slower, there are more movments and they become smaller. In addition the information content gets higher.