Dogs Are Either Optimists Or Pessimists

Wow, isn't science great! Canine psychologists from Bristol University, UK, have confirmed what many pet owners have long suspected: some dogs have a more gloomy outlook on life than others. The unusual insight emerged from a study into how dogs behave when separated from their owners.

Dogs that were generally calm when left alone were also found to have a 'dog bowl half full' attitude to life, while those that barked, relieved themselves and destroyed furniture, appeared to be more pessimistic, the study concluded.

Here's a picture of a pessimistic and an optimistic dog. Can you tell the difference?