Are expectations of obstructed facial features accurate?

Abstract

To fill in missing facial information of partially obstructed, unfamiliar faces, it is believed that people form an accurate holistic expectation. In support of this claim, Winand (2022) demonstrated that participants could correctly match the bottom half of a face to its top half. Yet, the study is limited by the fact that participants may have been able to match the face halves using superficial characteristics such as shading and texture rather than the shapes and sizes of features. Therefore, the purpose of this study was to replicate Winand’s (2022) findings with a task in which such superficial matching strategies cannot be used. This was achieved by morphing images together to blur out such inconsistencies in the stimuli. Undergraduates (N=122) were shown the top and bottom halves of a face that belonged to either a single-identity (two photos of the same identity morphed together) or dual-identity (two different identities morphed together). Participants toggled between two randomly chosen bottom halves that belonged to either the same people shown in the top half or different people, and chose the bottom half that best matched the top half. Overall, accuracy was well above chance, but highest when choosing the best single-identity bottom half for a single-identity top. Thus, although incorporating another identity decreases accuracy, people are generally able to find similarities among the top and bottom half identities without the aid of superficial characteristics. This suggests that people accurately form a holistic expectation based on the available top features.