(NaturalNews) Dogs have an intellectual capacity similar to that of a two-year-old human child, researcher and author Stanley Coren said at a presentation to the 117th annual convention of the American Psychological Association."One of the most recent breakthroughs is that people began to use tests which were originally designed for young humans -- for pre-linguistic or limited-linguistic humans -- to see whether dogs had certain capacities," Coren said. "And that allows you then to do a whole bunch of things, not only to determine whether a dog has a certain thinking skill but to place him in terms of where would you be in terms of human beings, as well as in terms of other animals."According to Coren, who has written more than a dozen books on understanding dogs, recent studies have confirmed that the animals have a higher cognitive capacity than scientists had thought. They are able to learn the meaning an average of 165 words, including hand signals; the record for most words learned tops 200. Coren said that dogs are also capable of performing basic arithmetic that involves counting up to four or five, and that they have been shown to intentionally deceive humans or other dogs.Coren also reported on studies comparing the intelligence of different breeds of dogs. He noted that there are three different kinds of dog intelligence: instinctive intelligence, which is highly breed-dependent; adaptive intelligence, which involves problem-solving and learning from the environment; and working and obedience, which involves trainability.According to measures of working and obedience intelligence only, the top seven "smartest" dogs are border collies, poodles, German shepherds, golden retrievers, dobermans, Shetland sheep dogs and Labrador retrievers. The hounds have the lowest degree of obedience intelligence."We all want insight into how our furry companions think, and we want to understand the silly, quirky and apparently irrational behaviors [that] Lassie or Rover demonstrate," Coren said. "Their stunning flashes of brilliance and creativity are reminders that they may not be Einsteins but are sure closer to humans than we thought."Sources for this story include: www.usatoday.com;