Abstract
Attribution of certain psychological or behavioural traits assessed from faces is frequently associated with specific shapes and proportions of morphological traits. Static photographs are currently the most often employed method in the research on social perception.
The method of photo acquisition might affect depicted subject’s shapes and proportions. However, it is currently not known what settings might affect social perception.
An important factor influencing the resulting photo is focal length, as shorter focal lengths produce high level of barrel distortion. Here we tested whether different focal lengths affect perception of female and male faces and bodies.
Results showed that female facial photos taken with the 50 mm focal length were rated as least feminine and least attractive. Ratings of photos of female bodies did not differ significantly in relation to the focal length used.
Photos of males´ faces and bodies were rated as significantly different in the following manner: the 50 mm focal length as least masculine and least dominant, the 105 mm focal length as most masculine and most dominant. Our results suggest that methodology of photo acquisition can influence results of studies using photos as stimuli; at least increase the chance of type II error (e. g., floor or ceiling effect).
Here we show evidence that focal length affects perception of female and male faces and male bodies, probably due to different levels of distortion that influence shapes and proportions of morphological traits. Thus, we recommend that the focal length should be kept constant, at least within individual studies and we stress the need to employ a precise methodology employed in future studies.