Dog psychologist Stanley Coren says that, based upon various behavioral measures, dogs have the mental ability of a human child age 2 to 2.5 years.
The writer of the Chronicle report is not convinced. He says:
My 2-year, 2-month-old kid can have a conversation on the phone with her grandparents. Not sure my dog can.
Anyway, the average dog can apparently learn about 165 words and signals, while the smartest dogs can probably learn up to about 250 words. They can also count to four or five.
One commenter to the article said:
...as long as my dog remembers to fetch and I don't get my feet wet...then he can be as dumb as dirt!
1. Border Collie (pictured in typical sheep herding pose)
3. German Shepherd
4. Golden Retriever
5. Doberman Pinscher
The five least intelligent breeds are:
107. Chow Chow
108. Bull dog
110. Afghan Hound