Figure 3: Social behavior test between two individuals a. The behavioral test scheme of the top and side (left) view with the position of five video cameras and several behavioral parameters for quantification, head center movement direction, and head-nose direction angles, i.e., absolute angle (phi) or relative to others (theta). The right middle images were the infrared thermo camera image data b. Local preference was defined as area where the subject stayed frequently and higher (H)/lower (L) part was distinguished. The area G, E, C, and O indicates grouping, escaping, centering, and other