Inside of a Dog_ What Dogs See, Smell, and Know - Alexandra Horowitz [145]
This could be another way of accounting for Rico's ability to pick the toy with the unfamiliar name out of a pile of toys: he selected the toy that he did not recognize.
With age, dogs sleep more but enter paradoxical—REM—sleep less than in youth. Scientists have theories but no final explanation for why dogs dream—and they dream vividly, if their eye fluttering, claw curling, tail twitching, and yelping in sleep is any indication. As in humans, one theory names dreams the accidental result of paradoxical sleep, which itself is a time of bodily restoration; alternatively, dreams might function as a time to practice, in the safety of one's imagination, future social interactions and physical feats or to review interactions and feats past.
When animals pass the test, skeptics highlight the logical fallacy of the conclusion: that self-aware humans use a mirror to examine ourselves does not imply that using a mirror requires self-awareness. When animals fail the test, the debate goes the other way: there is no good evolutionary reason why animals should examine something non-irritating on their heads, even if they recognized themselves. In either event, the mirror test continues to be the best test thus far developed for self-awareness, and one that uses simple equipment to boot.
I do not know if the origin of the myth of dog years—that dogs live the equivalent of seven years for every one of our years—has ever been cracked. I'd guess that it is a backward extrapolation from the length of the expected lifetime of humans (seventy+ years) to the expected lifetime of dogs (ten to fifteen). The analogy is more convenient than it is true. There is no real life-length equivalence except that we both are born and die. Dogs develop at lightning speed, walking and eating on their own in their first two months; human infants take over a year. By a year, most dogs are accomplished social actors, able to navigate dog and human worlds easily. The average child might be there by four or five. Then dog development slows, while human development skyrockets. If committed to the comparison, one could make a case for a sliding scale ratio: around 10 to 1 in their first two years, then diminishing to more like 2 to 1 in their last years. But the truly committed should consider the critical-period windows, the performance on cognitive tests, the diminishment of sensory capacities with age, and the lifespans of different breeds in their calculus.
This is similar to what has been called ontogenetic ritualization: the co-shaping by individuals of a behavior over time, until even the very initial part of the behavior carries meaning for them. In humans, an eyebrow-raise from one friend to another can take the place of a spoken commentary; as we've seen, among dogs a quick head-raise might replace an entire play bow.
Which some wolves instinctively do: even as young cubs they burrow their noses into a patch of land, drop a bone, nose-burrow some more, then proudly leave their poor excuse of a hole with a bone obviously visible. As adults they refine the behavior and do retrieve cached food—although there is no data about whether the retrieval is time-sensitive.
The medieval policy seems ridiculous to presume that dogs merit lawful consideration. It may seem equally ridiculous that our modern policy presumes that dogs do not: we still kill dogs who mortally wound a human—but now we call the dogs "dangerous" and do not bother to put them on trial (though their owners might be tried).
The command varies from owner to owner—from no! to the recently popular leave it! Each is fundamentally a negation: a sharp-sounding grammatical flourish that can be applied concurrently