Toronto, Aug 10 - Dogs can intentionally deceive other dogs and people to get treats and can understand more than 150 words, according to a psychologist and leading canine researcher.

Stanley Coren of the University of British Columbia (UBC), who has authored several popular books on dogs and dog behaviour, has reviewed numerous studies to conclude that dogs have the ability to solve complex problems and are more like humans and higher primates.

'We all want insight into how our furry companions think, and we want to understand the silly, quirky and apparently irrational behaviours Lassie or Rover demonstrate,' Coren said in an interview.

'Their stunning flashes of brilliance and creativity are reminders that they may not be Einsteins but are sure closer to humans than we thought.'

During play, dogs are capable of deliberately trying to deceive other dogs and people in order to get rewards, said Coren. 'And they are nearly as successful in deceiving humans as humans are in deceiving dogs.'

According to several behavioural measures, Coren says dogs' mental abilities are close to a human child aged two to two and a half years.

The intelligence of various types of dogs does differ and the dog's breed determines some of these differences.

'There are three types of dog intelligence: instinctive (what the dog is bred to do), adaptive (how well the dog learns from its environment to solve problems) and working and obedience (the equivalent of 'school learning').