As far as the "intelligent" part, she's the dog who learned to open the slide bolts on our fence by watching us do it only two or three times. I wouldn't have believed it unless I'd seen it with my own eyes. She also took her job very seriously, and by "job" I mean "life." She had a passion for catching frisbees, but I always got the impression that it wasn't because it was fun. It was because the Russian judge had only given her a 9.4 on the previous catch and she was determined to improve her score.
There were ways in which her intelligence was almost eerie at times. I was away from home one time and called Carol to say hi, and apparently Doolin looked at her with question marks in her eyes. Carol said, "Doolin, it's Daddy!" Doolin responded by becoming extremely excited and running around the house looking in all of the likely spots -- my office, the recliner, the workshop -- as well as some somewhat less likely places like under the bed. When the search was unsuccessful, apparently she seemed extremely worried for the rest of the evening.
Not that this was all that different from her usual expression.
One thing that always puzzled us, though, was her ability to sense when we were about to get home. Doolin would routinely go to the door and stand there on guard before Carol's car pulled into the driveway. She did the same thing, I heard, when I was about to arrive. In each case, there was no obvious cue that she could have relied on; we live on a fairly well-traveled stretch of rural highway and even if she heard our cars in the distance, I can't imagine they sound that different from any of the other hundreds of cars that pass by daily. And my arrival time, especially, varied considerably from day to day, because of after-school commitments. How, then, did she figure out we were about to get home -- or was it just dart-thrower's bias again, and we were noticing the times she got it right and ignoring all the times she didn't?
According to Alexandra Horowitz, a professor of psychology at Barnard University, there's actually something to this observation. There are hundreds of anecdotal accounts of the same kind of behavior, enough that (although there hasn't been much in the way of a systematic study) there's almost certainly a reason behind it other than chance. Horowitz considered the well-documented ability of dogs to follow a scent trail the right direction by sensing where the signal was weakest -- presumably the oldest part of the trail -- and heading toward where it was stronger. The difference in intensity is minuscule, especially given that to go the right direction the dog can't directly compare the scent right here to the scent a half a kilometer away, but has to compare the scent here to the scent a couple of meters away.
What Horowitz wondered is if dogs are using scent intensity as a kind of clock -- the diminishment of a person's scent signal after they leave the house gives the dog a way of knowing how much time has elapsed. This makes more sense than any other explanation I've heard, which include (no lie) that dogs are psychic and are telepathically sensing your approach. Biological clocks of all kinds are only now being investigated and understood, including how they are entrained -- how the internal state is aligned to external cues. (The most obvious examples of entrainment are the alignment of our sleep cycle to light/dark fluctuations, and seasonal behaviors in other animals like hibernation and migration in response to cues like decreasing day length.)
So it's possible that dogs are entraining this bit of their behavior using their phenomenally sensitive noses. It'll be interesting to see what Horowitz does with her hypothesis; it's certainly worth testing. Now, I need to wrap this up because Guinness's biological clock just went off and told him it was time to play ball. Of course, that happens about fifty times a day, so there may not be anything particularly surprising there.
This week's Skeptophilia book of the week is brand new; Brian Clegg's wonderful Dark Matter and Dark Energy: The Hidden 95% of the Universe. In this book, Clegg outlines "the biggest puzzle science has ever faced" -- the evidence for the substances that provide the majority of the gravitational force holding the nearby universe together, while simultaneously making the universe as a whole fly apart -- and which has (thus far) completely resisted all attempts to ascertain its nature.
Clegg also gives us some of the cutting-edge explanations physicists are now proposing, and the experiments that are being done to test them. The science is sure to change quickly -- every week we seem to hear about new data providing information on the dark 95% of what's around us -- but if you want the most recently-crafted lens on the subject, this is it.
[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]