 Equally, the threshold at which aggression is shown may be influenced by a range of medical factors, or, in some cases, precipitated entirely by pathological disorders.Hence, the contextual and physiological factors present when two dogs first encounter each other may profoundly influence the long-term nature of the relationship between those dogs.The complexity of the factors involved in this type of learning means that dogs may develop different "expectations" about the likely response of another individual for each resource in a range of different situations.