“…Second, in some studies investigating the effect of the babyface schema, neutral infant face images were mainly used as the experimental materials (Brosch et al, 2007; Cheng et al, 2015; Franklin et al, 2018; Glocker, Langleben, Ruparel, Loughead, Gur, & Sachser, 2009; Glocker, Langleben, Ruparel, Loughead, Valdez, et al, 2009; Hahn et al, 2013; Jia, Cheng, et al, 2019; Parsons et al, 2013; Parsons, Young, Kumari, et al, 2011), which greatly limited the external validity of such studies. In fact, when an adult interacts with an infant, the facial expression of the infant is an important cue for the adult to judge the infant’s physical and mental states (Sullivan, 2014). For example, a study observed that when evaluating infant faces, adults thought that happy or neutral infant faces were cuter than sad infant faces, and adults perceived a stronger self-reported willingness to adopt (Aradhye et al, 2015).…”