This article proposes a new criterion for assessing an animal’s capacity for suffering, focusing on psychological criteria, particularly avoidance learning. This criterion may allow for a more comprehensive assessment of suffering in various species and situations. The theory of integrative levels explains the development of avoidance behavior and presents the probable cognitive threshold for animal suffering. Animals capable of avoidance learning are more likely to suffer, as this behavior requires the ability to form associations between stimuli and actions and make predictions about future events, which may lead to aversive emotional states. The proposed criterion offers an objective way to assess suffering without relying on ambiguous terms like “consciousness” or “sentience,” providing a broader, more accurate evaluation method.