In Langois and Roggman's research, what method did they use to show that composite faces can be more attractive?

Langois and Roggman's research demonstrated that composite faces can be perceived as more attractive by utilizing the method of digitizing and averaging multiple faces. By creating composite images, they were able to combine features from different faces into a single image. This averaging process tends to enhance symmetry and other characteristics that are associated with attractiveness in human faces.

Research has indicated that people often find average or composite faces more appealing because these images minimize individual imperfections and accentuate desired traits that are typically considered attractive. As a result, the study provides evidence supporting the idea that we perceive composite faces as more attractive due to their mathematical and psychological appeal, which is rooted in the perception of beauty across different cultures.

The other options, while related to altering faces for aesthetic effects, do not address the fundamental method used to create attractiveness through averaging and synthesis of multiple face features.