“…Moreover, a sexually immature group like children is not a good sample group for studying gender differences (Norscia, Demuru, & Palagi, 2016b). Second, 5 of the 15 studies did not include a baseline condition to control for spontaneous yawning ( Bartholomew & Cirulli, 2014 ; Eldakar et al., 2015 ; Gallup, Church, Miller, Risko, & Kingstone, 2016 ; Gallup & Eldakar, 2011 ; Massen, Dusc, Eldakar, & Gallup, 2014 ). A control condition (i.e., in our case, a smiling video) or a baseline measurement (e.g., spontaneous yawning in Norscia et al., 2016a ) offers an assurance that the recorded yawning was not predominantly spontaneous yawning, which is known to have no gender difference ( Schino & Aureli, 1989 ), but contagious yawning which was our central research interest.…”