Dogs are prone to complex emotions such as jealousy and pride, according to scientific research that sheds new light on their relationship with humans.    Dogs do not like seeing their owners offering affection to other creatures, especially other dogs, and react negatively when their owners bring home new partners, the research found.   Psychologists previously believed most animals lack the "sense of self" needed to experience so-called secondary emotions such as jealousy, embarrassment or guilt. These emotions are more complex than feelings associated with instant reaction such as anger, lust or joy.      Dr Friederike Range, of theprefix = st1 /UniversityofVienna's neurobiology department, has shown that dogs feel intensely jealous when they spot that they are unfairly treated compared with other dogs.      The dog study is the latest into several species, including cows, horses, cats and sheep, which have shown that animals are far more self-aware than we thought.      Dr Paul Morris, a psychologist at theUniversityofPortsmouthwho studies animal emotions, told The Sunday Times, "We are learning that dogs, horses, and perhaps many other species are far more emotionally complex than we ever realised. They can suffer simple forms of many emotions we once thought only primates   could experience. "      In research among dog owners, Dr Morris found almost all of them reported jealous behaviour by their pets. The dog often tried to keep their owner away from a new lover in the early days of a relationship.      Behavioural experts recommend owners keeping their dogs' routine as much as possible when a new partner or child comes along in order to prevent jealous activities from the dog such as interruptions with barking. Which of the following is the best title?
Dogs, the favorite pets Dogs can be jealous Dogs can be angry A discovery about animal behaviour