0:00:06.407,0:00:10.201 Your dog loves to curl up on the couch,[br]but so do you, 0:00:10.201,0:00:13.703 so you shoo him off[br]and settle in for a cozy evening. 0:00:13.703,0:00:15.918 After all, you're the human around here. 0:00:15.918,0:00:19.481 You're an intelligent being,[br]not a simple creature of instinct. 0:00:19.481,0:00:22.591 You can plan and dream, and oh- 0:00:22.591,0:00:25.814 Did your dog just outsmart you[br]and feel happy about it? 0:00:25.814,0:00:28.190 Or was he just following his instincts? 0:00:28.190,0:00:29.858 Is there even a difference? 0:00:29.858,0:00:31.687 What is he thinking? 0:00:31.687,0:00:34.452 Well, it depends on [br]what we mean by "thinking" 0:00:34.452,0:00:37.603 and the criteria we use to evaluate it. 0:00:37.603,0:00:42.165 Aristotle and Descartes both use [br]the criteria of instinct and intelligence 0:00:42.165,0:00:44.889 to divide animals from humans. 0:00:44.889,0:00:47.714 Aristotle believed [br]that humans possess reason, 0:00:47.714,0:00:53.220 while animals could only follow brute[br]instincts for survival and reproduction. 0:00:53.220,0:00:55.294 Almost 2000 years later, 0:00:55.294,0:00:59.565 Descartes suggested [br]a more extreme version of that idea, 0:00:59.565,0:01:03.714 arguing that animals following instincts[br]were indistinguishable 0:01:03.714,0:01:09.098 from robots responding mechanically [br]to stimuli in their environments. 0:01:09.098,0:01:13.058 But the consensus against animal [br]intelligence began to unravel 0:01:13.058,0:01:15.852 with Darwin's Theory of Evolution. 0:01:15.852,0:01:20.827 Darwin hypothesized that intelligence[br]could evolve from simpler instincts. 0:01:20.827,0:01:25.875 He had observed earthworms making choices[br]about how to drag oddly shaped leaves 0:01:25.875,0:01:27.441 into their boroughs, 0:01:27.441,0:01:32.580 and was struck that a human might employ[br]similar means to solve a similar problem. 0:01:32.580,0:01:37.139 And if, as he thought, humans [br]are descended from simpler creatures, 0:01:37.139,0:01:41.869 then perhaps our minds lie[br]at the far end of a continuum, 0:01:41.869,0:01:46.647 differing from theirs in degree,[br]but not in kind. 0:01:46.647,0:01:50.632 Recent experiments showing that many[br]species can solve complex problems 0:01:50.632,0:01:53.907 confirm Darwin's initial hypothesis. 0:01:53.907,0:01:57.371 Elephants use objects to reach[br]inaccessible places. 0:01:57.371,0:01:59.497 Crows make their own tools, 0:01:59.497,0:02:02.835 and can use water displacement [br]to get a reward. 0:02:02.835,0:02:06.713 Octopuses can open jars [br]after watching others do so, 0:02:06.713,0:02:10.022 and can even remember [br]the process months later. 0:02:10.022,0:02:13.438 Such tasks involve considering [br]aspects of a problem 0:02:13.438,0:02:18.822 separately from the immediate situation,[br]and retaining the strategy for later use. 0:02:18.822,0:02:22.390 Still, while animals [br]can solve complex problems, 0:02:22.390,0:02:25.922 how do we know what, or even that, [br]they are thinking? 0:02:25.922,0:02:29.649 Behaviorists, such as Pavlov[br]and Thorndike, argue 0:02:29.649,0:02:31.828 that animals that appear to think 0:02:31.828,0:02:35.528 are usually only responding [br]to reward or punishment. 0:02:35.528,0:02:38.254 This was the case with Clever Hans, 0:02:38.254,0:02:43.324 a horse with the amazing ability[br]to tap out answers to math problems. 0:02:43.324,0:02:46.953 But it turns out Hans [br]wasn't especially good at math, 0:02:46.953,0:02:51.991 but at reading his unwitting [br]trainer's subtle nonverbal cues 0:02:51.991,0:02:54.567 for when to stop tapping. 0:02:54.567,0:02:58.838 So Hans couldn't count,[br]but does that mean he wasn't thinking? 0:02:58.838,0:03:02.109 After all, he could interpret [br]nuanced social messages, 0:03:02.109,0:03:06.389 a quality he shared with many other[br]non-human animals. 0:03:06.389,0:03:09.690 Elephants recognize each other[br]after years apart, 0:03:09.690,0:03:12.674 and even seem to mourn their dead. 0:03:12.674,0:03:15.759 Bees communicate [br]using a special waggle dance 0:03:15.759,0:03:20.575 to indicate the location and quality [br]of a food source to other bees. 0:03:20.575,0:03:24.707 Chimpanzees engage [br]in complex deception schemes, 0:03:24.707,0:03:29.689 suggesting not only do they think,[br]but they understand that others do, too. 0:03:29.689,0:03:32.398 And then there is Alex the Grey Parrot, 0:03:32.398,0:03:33.902 who could use human language 0:03:33.902,0:03:37.491 to distinguish the colors [br]and shapes of absent objects, 0:03:37.491,0:03:42.672 and even understand abstract concepts,[br]like bigger and smaller. 0:03:42.672,0:03:44.660 That sounds a lot like intelligence, 0:03:44.660,0:03:47.649 and not just the work [br]of mindless machines. 0:03:47.649,0:03:52.338 But while a non-human animal can solve[br]problems and even communicate, 0:03:52.338,0:03:56.252 for humans, thinking [br]also involves consciousness, 0:03:56.252,0:04:01.105 the ability to reflect on our actions,[br]not simply to perform them. 0:04:01.105,0:04:06.370 So far, none of our studies tell us[br]if having the intelligence to outsmart us 0:04:06.370,0:04:10.959 means that our dog [br]can also feel good about doing so. 0:04:10.959,0:04:14.596 What we really want to know is[br]what is it like to be a dog, 0:04:14.596,0:04:16.006 or an octopus, 0:04:16.006,0:04:17.519 or a crow? 0:04:17.519,0:04:20.602 Philosophers of mind call this[br]The Hard Problem, 0:04:20.602,0:04:24.351 because while you and I can report[br]what it feels like to be a human, 0:04:24.351,0:04:26.316 nobody speaks horse. 0:04:26.316,0:04:28.496 Even a talking parrot, like Alex, 0:04:28.496,0:04:32.989 couldn't tell us how he feels [br]about the colors he could name. 0:04:32.989,0:04:35.493 And what if consciousness [br]comes in different forms? 0:04:35.493,0:04:38.769 Would we even recognize [br]the consciousness of bees? 0:04:38.769,0:04:43.530 For that matter, how can we know for sure[br]that other people have consciouness? 0:04:43.530,0:04:46.580 Perhaps they're just [br]well-functioning zombies. 0:04:46.580,0:04:51.231 Regardless, animal minds continue to test[br]the limits of our understanding 0:04:51.231,0:04:56.524 and how we frame them may reveal more[br]about our minds than theirs.