The research was carried out by the University of Edinburgh and compared domestic cats to their wildcat and big cat relatives

New research claims that despite looking cute and harmless, the sparkle in your beloved cat’s eyes might is probably their killer instinct.

Researchers from the University of Edinburgh looked at the character traits of domestic pet cats and compared how similar their behaviour is to wildcats and big cats such as lions .

The study found that the different breeds had the same strong characteristics related to dominance, impulsiveness and neuroticism.

Compared with the snow leopard, the Scottish wildcat and the African lion, researchers found larger predators shared similar characteristics of aggression and neurotic behaviour to domestic cats.

And if the average domestic cat were any bigger, it too would probably try to kill you.

The cats were rated on the ‘Big Five’ human personality traits, using a scale of one to five.

These traits were: Openness to experience, conscientiousness, extraversion/introversion, agreeableness and neuroticism.

But the researchers, in cooperation with the Bronx Zoo, also rated cats on personality traits such as playfulness – and it’s not all bad news.

Cats were rated highly for being playful and excitable.

Psychologist Dr Max Watchel said cat owners need to remember that by keeping one as a pet, they are inviting “little predators” into their home.

Dr Wachtel told 9NEWS: “It is good to understand the personality characteristics of our pets. Different cats have different personalities. But as a species, there are a lot of commonalities.

“They’re cute and furry and cuddly, but we need to remember when we have cats as pets, we are inviting little predators into our house.

“For a lot of people, it is worth it. Cats can be fantastic, sweet companions. Until they turn on you.”