How much do dogs understand when humans talk to them?

Victoria Gill took on this question...

维多利亚,似乎是en a number put on the number of words that a dog can understand, a bit like the human lexicon I guess, and that's approximately 200. That was a dog called Rico which sadly passed away in 2008. But Rico was studied at the Max Planck Institute for Evolutionary Anthropology in Leipzig and they do a lot of work on this stuff, understanding how dogs have adapted to human culture and language. But that seems to be the maximum and it does really vary according to breed. Rico was a border collie and that's a working dog that's been bred and trained for its ability to be able to understand and work with a man, to run sheep and respond to those commands. So that's something that's been bred into that line, but when you have breeds that are maybe bred for their appearance, they might be suffering a little bit on the intellect.

Chris - Certainly, my mum had a dog. Unfortunately, he has now died as well, but he had an exceptional vocabulary and the other thing that they were saying dogs seem to be able to do is - in the experiments with Rico - they would have him in a room and say, "Got and get a toy of type X from the room next door" and then not include that toy in the line-up of toys that he did know the name for and he would assume that because he didn't know what that toy was named and he had been told to go and get things but he didn't have the name for, that must be the one, and that's the same sort of learning process as the 3-year-old child shows. It's quite extraordinary that they're able to do this, but then on the other hand, given that they are mammals and so, we have common ancestors, is it so surprising?

Victoria - It is extraordinary. I think it does show a level of adaptation and how quickly it's been bred into dogs - into their breeding lines - that they can cope with this sort of communication with humans. The other thing that they've shown in these kinds of tests is that there seems to be a real connection between the dog and the owner. So, the specific human that the dog's associated with that they're more likely to understand fully the commands and even respond to that facial expressions - the dog's owner and they recognise that person.