The debate about animal emotions relies heavily on empirical evidence, which is often open to multiple interpretations. This ambiguity allows researchers at either end of the spectrum to perceive support for their positions in study results. Thus, evidence reported by Cook and colleagues (2018) – that dogs’ trait aggression is associated with their amygdala activation when watching their caregivers feed a fake dog – may be interpreted by some as neural evidence for jealousy in dogs and by others as an artefact of the study design. I argue that the discussion should be complemented with a greater consideration of theoretical arguments about the (social) functions of emotions. Theory and research on the intrapersonal and interpersonal effects of emotions are consistent with the hypothesis that various non-human social animals can experience and communicate emotions, although the labeling of these emotions is not self-evident