Pets can provide a good indication of their owners' personalities, a new study has shown.

People who have dogs tend to be cheerful, while cat lovers are dependable and emotionally sensitive, and reptile owners independent.

But no-one is happier than a keeper of tropical fish, according to the research.

Fish owners stand out as the most contented of individuals, says psychologist Professor Richard Wiseman, who led the study.

Almost 60% are convinced that their fishy friends have a personality and sense of humour.

The research reveals that pets' personalities often mirror those of their owners.

"If you ask someone walking their dog what kind of personality their dog has, they're likely to give away a lot about themselves," said Prof Wiseman.

Previous studies have shown that pet owners often show a physical resemblance to their pets.

"This work suggests that they may also think alike," said Prof Wiseman, from the University of Hertfordshire. "Interestingly, this similarity increased over time, suggesting that pets may slowly come to adopt their owner's personality, or vice versa."

More than 2,000 owners were invited to give details about both their own and their pets' personalities via a psychological questionnaire posted on a website.

Analysing the results revealed that different kinds of people chose to have different types of pet.

In many cases, owners believed they and their animal companions were psychologically similar.

Dogs and dog owners emerged as cheerful, playful and fun-loving, while cat owners regarded both themselves and their pets as emotional and sensitive.

"Part of it is that people choose animals that reflect their own personality from the start," said Prof Wiseman. "If you're playful, owning a dog is going to be more up your street than having a cat. However, there might be more to it than that. There's evidence that over time personality is contagious. If you live with a neurotic person for 20 years, you're likely to become neurotic yourself. The same might apply to pet owners and their pets."

He said American research had shown that when strangers were asked to look after people's pets, they and the owners independently gave the animals similar personality ratings.

It may be hard to think of fish having personality, but fish owners insist that they do, said Prof Wiseman.

"Around 60% think their fish have a sense of humour," he added. "I'm not sure how that works. On the other hand, people who keep lizards and snakes don't think their pets have a sense of humour, and those owners are pretty humourless too.

"On the questionnaire, one in four reptile owners said they did not have a sense of humour, which is very high figure. Normally, 94% of people think their sense of humour is above average."

Based on the ratings given by their owners, the study suggested that 62% of dogs, 57% of fish, 48% of cats, 42% of horses, 38% of birds, and zero per cent of reptiles had a good sense of humour.

Prof Wiseman is continuing his research and asking pet owners to visit the web address www.petpersonality.co.uk.

He is now looking for owners with more unusual or exotic pets.

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