Why Do Large Dogs Sound More Aggressive to Human Listeners: Acoustic Bases of Motivational Misattributions

Previous research has highlighted that while human listeners are capable of estimating the body size of dogs using the acoustic components of their growls, they also rate growls from larger dogs as more being aggressive than growls from smaller dogs. The aim of this study was to investigate the relative contributions of two cues to body size, funda- mental frequency (F0) and formant frequency dispersion (Df) to per- ceived levels of aggression. We found that participants that had just made an accurate assessment of caller size based on these characteristics then misattributed aggressiveness levels on the basis of these same size- related acoustic cues. More specifically, stimuli in which F0 andor Df were typical of larger dogs were rated as being more aggressive than stimuli typical of smaller dogs. Although both F0 and Df influenced aggressiveness ratings independently, their interaction also had a signifi- cant affect. These results are discussed with respects to the human ten- dency to generalise reliable between-class acoustic cues to within-class stimuli and the resulting potential for making perceptual misattributions