Your dog loves to curl up on the couch, but so do you,
so you shoo him off and settle in for a cozy evening.
After all, you're the human around here.
You're an intelligent being, not a simple creature of instinct.
You can plan and dream, and oh-
Did your dog just outsmart you and feel happy about it?
Or was he just following his instincts?
Is there even a difference?
What is he thinking?
Well, it depends on what we mean by "thinking"
and the criteria we use to evaluate it.
Aristotle and Descartes both use the criteria of instinct and intelligence
to divide animals from humans.
Aristotle believed that humans possess reason,
while animals could only follow brute instincts for survival and reproduction.
Almost 2000 years later,
Descartes suggested a more extreme version of that idea,
arguing that animals following instincts were indistinguishable
from robots responding mechanically to stimuli in their environments.
But the consensus against animal intelligence began to unravel
with Darwin's Theory of Evolution.
Darwin hypothesized that intelligence could evolve from simpler instincts.
He had observed earthworms making choices about how to drag oddly shaped leaves
into their boroughs,
and was struck that a human might employ similar means to solve a similar problem.
And if, as he thought, humans are descended from simpler creatures,
then perhaps our minds lie at the far end of a continuum,
differing from theirs in degree, but not in kind.
Recent experiments showing that many species can solve complex problems
confirm Darwin's initial hypothesis.
Elephants use objects to reach inaccessible places.
Crows make their own tools,
and can use water displacement to get a reward.
Octopuses can open jars after watching others do so,
and can even remember the process months later.
Such tasks involve considering aspects of a problem
separately from the immediate situation, and retaining the strategy for later use.
Still, while animals can solve complex problems,
how do we know what, or even that, they are thinking?
Behaviorists, such as Pavlov and Thorndike, argue
that animals that appear to think
are usually only responding to reward or punishment.
This was the case with Clever Hans,
a horse with the amazing ability to tap out answers to math problems.
But it turns out Hans wasn't especially good at math,
but at reading his unwitting trainer's subtle nonverbal cues
for when to stop tapping.
So Hans couldn't count, but does that mean he wasn't thinking?
After all, he could interpret nuanced social messages,
a quality he shared with many other non-human animals.
Elephants recognize each other after years apart,
and even seem to mourn their dead.
Bees communicate using a special waggle dance
to indicate the location and quality of a food source to other bees.
Chimpanzees engage in complex deception schemes,
suggesting not only do they think, but they understand that others do, too.
And then there is Alex the Grey Parrot,
who could use human language
to distinguish the colors and shapes of absent objects,
and even understand abstract concepts, like bigger and smaller.
That sounds a lot like intelligence,
and not just the work of mindless machines.
But while a non-human animal can solve problems and even communicate,
for humans, thinking also involves consciousness,
the ability to reflect on our actions, not simply to perform them.
So far, none of our studies tell us if having the intelligence to outsmart us
means that our dog can also feel good about doing so.
What we really want to know is what is it like to be a dog,
or an octopus,
or a crow?
Philosophers of mind call this The Hard Problem,
because while you and I can report what it feels like to be a human,
nobody speaks horse.
Even a talking parrot, like Alex,
couldn't tell us how he feels about the colors he could name.
And what if consciousness comes in different forms?
Would we even recognize the consciousness of bees?
For that matter, how can we know for sure that other people have consciouness?
Perhaps they're just well-functioning zombies.
Regardless, animal minds continue to test the limits of our understanding
and how we frame them may reveal more about our minds than theirs.