The Recursive Mind: The Origins of Human Language, Thought, and Civilization - Michael C. Corballis 2014
Notes
CHAPTER 1
What Is Recursion?
1. For a useful discussion, see Fitch (2010b), who identifies three different meanings of the word “recursion.”
2. From Littlewood 1960, 40.
3. Lost in the Funhouse, by John Barth (1969).
4. This was actually a parody on the earlier poem by the seventeenth-century writer Jonathan Swift:
So nat’ralists observe, a flea
Hath smaller fleas that on him prey,
And these have smaller fleas that bite ’em,
And so proceed ad infinitum
My favorite, though, is Ogden Nash’s flea-like poem, said to be the shortest ever written:
Adam
Had ’em.
5. In case you’re old-fashioned, I use * rather than × to mean “multiplied by.”
6. Some readers may recognize the Fibonacci series from Dan Brown’s book The Da Vinci Code, where the first eight digits of the series provided the number of a critical bank account.
7. Pinker and Jackendoff 2005, 203.
8. Fitch 2010a.
9. Pinker and Jackendoff 2005, 230.
10. A case in point is a claim that starlings can parse recursive sequences of sounds (Gentner et al. 2006), leading to a headline in the New York Times of 2 May 2006 that read, “Starlings may Shed Light on Language.” It turns out that there is a simpler explanation for what the starlings were able to achieve. This is discussed more fully in chapter 3.
11. Chomsky 1995.
12. The champion may be an African grey parrot, who could count accurately up to about six (Pepperberg 2000). This kind of counting is known as subitization (Kaufman et al. 1949), as opposed to the iterative/recursive counting that allows us to count indefinitely.
13. Chomsky (1988, 256) wrote that “human language has the extremely unusual, possibly unique property of discrete infinity.”
14. This is recursive embedding of mental states, in that Sir Toby’s anticipation is embedded in what Maria foresees, Olivia’s judgment is embedded in what Sir Toby anticipates, and so on.
15. You can find it, needless to say, on the Web.
16. From Saki’s story “The hounds of fate”—see Saki 1936.
17. Hennessy 1995.
18. In some cases, iterative processes can achieve the same effect as recursive ones. Earlier, I showed how recursion can be used to generate infinite mathematical series, such as the natural numbers or the Fibonacci series, but the same series can be generated iteratively. To generate the natural numbers, for example, one can simply program an instruction that might read as follows:
Define function successor [while i > 0: print i + 1].
When the number 1 is entered, the string of integers will be printed forever, or the printer wears out—or someone kindly switches it off. Similarly, one might generate the Fibonacci series as follows:
Define function fibonacci [while i > 1: print {(i − 1)+(i − 2)}].
These definitions are not themselves recursive in that the function does not call on itself, but they can operate indefinitely if each output is fed back into the function as the next input.
19. An example familiar to psychologists is factor analysis. The problem is to estimate so-called communalities, which are the (unknown) diagonal elements in a correlation matrix. You start by guessing what the communalities might be, compute a factor solution, from which new communalities are computed. You then repeat the process until the communalities stabilize. As a punishment for missing labs, I was once forced to compute a solution by hand. It took hours, but those were the days before computers.
20. The approach also owed much to Jerry Fodor’s (1983) book The Modularity of Mind, although Fodor himself, in response to Pinker’s How the Mind Works, wrote a book entitled The Mind Doesn’t Work That Way. Part of his objection seems to be to what he calls the “massive modularity hypothesis,” which is the idea that the whole damn thing is modular, and part to the incorporation of modules into a Darwinian view of mental evolution. I use the term “evolutionary psychology” to refer to the group of psychologists who adopt the basic tenets laid out by Barkow, Cosmides, and Tooby (1992). Other psychologists, such as myself, are interested in evolution, but don’t necessarily go along with all of these tenets.
21. Pinker 1997, 27.
22. Human evolution during the Pleistocene is further discussed in chapter 11, although not specifically from the perspective of the evolutionary psychologists.
23. One of the main proponents was William McDougall (1908).
24. Bernard 1924.
25. Pinker 1997, 315.
26. Cosmides 1985.
27. New, Cosmides, and Tooby 2007.
28. Quoted in Science, 318, 25 (2007).
29. Pinker 1997, 315.
30. Mithen 1996.
31. Premack 2007, 13866.
32. Read 2008. It is not clear whether the limitation is one of simple capacity, or whether chimpanzees lack the specific ability to store embeddings.
33. Throughout the book, I use the term “hominin” to refer to humans and their extinct bipedal ancestors, but not including chimpanzees and the other great apes. This is consistent with most current usage (e.g., Wood and Collard 1999), although some authors retain the term “hominid” for humans and their ancestry, and others include the great apes among the hominins.
PART 1
Language
1. Christiansen and Kirby 2003, 1.
CHAPTER 2
Language and Recursion
1. Müller 1873.
2. Butler 1919, 95.
3. Chomsky 1957.
4. Hauser, Chomsky, and Fitch 2002.
5. Karlsson 2007. I found no instances of three, or even two, levels of centerembedding in his article.
6. Ribena is a black-currant drink with a high concentration of vitamin C. It was heavily promoted in Britain during World War II, when other sources of Vitamin C were scarce.
7. A rewrite rule can be interpreted to mean “replace the expression on the left with the expression on the right.” I’m told that rewrite rules are now considered by linguists to be an old-fashioned way of showing the structure of sentences, but here they make the point.
8. Chomsky 1975. For a useful summary, see also Chomsky 2010, which also includes his views on the evolution of language.
9. Chomsky 2010, 59.
10. Crow 2010. See also note 4 in chapter 4.
11. Noam Chomsky, quoted in Piattelli-Palmarini 1980, 48.
12. Chomsky’s terminology has changed—one might even say evolved—over the years. In his early work he contrasted surface structure with deep structure. Deep structure seems to have given way to universal grammar, and more recently to I-language. Needless to say, these changes are accompanied by subtle changes in meaning.
13. Christiansen and Chater 2008.
14. Life among the Pirahã proved physically hazardous as well as linguistically impenetrable to a Westerner—see Everett’s book Don’t Sleep, There are Snakes (2008).
15. Everett 2005.
16. Everett 2005, 629.
17. Everett 2005, 634.
18. See the critique by Nevins, Pesetsky, and Rodrigues (2007) and the response by Everett (2007). The issue may depend on how recursion is defined. The Pirahã language may have no recursion in the sense of embedded phrases, but may still be recursive in the sense of Chomsky’s Merge operation. In the example of My saying John intend-leaves, the phrase My saying and intend-leaves might each be considered products of Merge, which are then themselves merged into the utterance (not strictly a sentence as it contains no verb).
19. Karlsson 2007.
20. Evans 2003, 633.
21. See especially Evans and Levinson 2009 and Evans 2009.
22. These various figures are from Evans 2009.
23. One can see the same processes at work in modern English, although they are no doubt held in check by the unifying influences of the media—radio, television, newspapers, the Internet. Young people seek new expressions to differentiate themselves from their elders, gangs develop gangspeak, and racial groups evolve ways of speaking that cannot be attributed wholly to a different first language. African American English, for example, cannot be attributed to an indigenous African language. Women develop ways of speaking that differ from the more gruff intonations of malespeak.
24. Evans 2009, 46.
25. Pinker and Bloom 1990, 715.
26. Tomasello 2003, 5.
27. Karlsson 2007.
28. Blatt 1957.
29. Chomsky 2010, 60.
30. The term grammaticalization is often taken to refer to processes that arise in languages that already have grammar. This implies a jump from protolanguage to language, which to my mind contains vestiges of “big bang” theory. An alternative view, which I prefer, is that language—and grammar—emerged gradually, so the very concept of protolanguage is unfounded. In NSL and ABSL, we are effectively witnessing the emergence of new languages. For an alternative viewpoint, though, see Arbib 2009.
31. For more detailed exposition, see Hopper and Traugott 2003, and Heine and Kuteva 2007.
32. Senghas, Kita, and Ôzyürek 2004.
33. See Kirby and Hurford 2002 for a review.
34. Stokoe, Casterline, and Croneberg 1965.
35. Aronoff et al. 2008.
36. Hockett 1960.
37. Hockett 1960, 90.
38. Aronoff 2007. Aronoff is proud to call himself an “antidecompositionalist”—one who is opposed to the view that words can be broken down into parts. Of course words can be broken down into parts, but Aronoff argues that this is not the way people actually use words, or think about them. The issue is complex and somewhat technical, and readers are referred to Aronoff’s article for more extensive discussion. Interestingly, Aronoff appeals to the “lexicalist” position described by Chomsky (1970) as support for his view.
39. Of course it’s more complicated than that, since English has evolved in many ways and includes lots of borrowing. The suffix -ed derives from ancestral Proto-German.
40. Givón 1971, 413.
41. Pinker 1994.
42. This phrase was coined by Marler (1991) to account for the acquisition of birdsong, but borrowed by Locke and Bogin (2006) to account for the human acquisition of language.
43. Everett 2005, 622.
44. Christiansen and Chater 2008.
45. Hauser, Chomsky, and Fitch 2002.
46. See Jackendoff 2002, 204.
CHAPTER 3
Do Animals Have Language?
1. Saki 1936, 122; first published in the collection The Chronicles of Clovis in 1911.
2. Jürgens 2002.
3. Provine 2000.
4. Goodall 1986, 125.
5. Arcadi, Robert, and Boesch 1998.
6. Schaller 1963.
7. Slocombe and Zuberbühler 2007.
8. Hopkins, Taglialatela, and Leavens 2007.
9. It is commonly believed that chimpanzees are a good model for the common ancestor we share with them. As we shall see in chapter 11, this notion is changing. Chimpanzees have probably changed as much as humans have since the split some six or seven million years ago.
10. Snowdon 2004, 132.
11. Although, confusingly, it has also been maintained that gorillas have the most complex and frequent vocalizations of the great apes (Harcourt and Stewart 2007).
12. Oddly enough, there is a novel by the late New Zealand writer Nigel Cox, called Tarzan Presley, in which Elvis is raised by gorillas in the Wairarapa district of New Zealand, before moving to the United States and establishing his career as a singer and rock star. As far as I know, there are no gorillas outside of zoos in New Zealand, although one or two may have invaded the rugby scrum.
13. Aitken 1981; Sutton, Larson, and Lindeman 1974.
14. MacLean and Newman 1988.
15. Hihara et al. 2003.
16. Roy and Arbib 2005.
17. Jarvis 2006.
18. Knight 1998.
19. Dawkins and Krebs 1978.
20. Or else, heaven help us, the sound of screwtops being unscrewed, since corks seem to be disappearing from Australian (and New Zealand) wine bottles. On the whole, I think this is a positive development, since I have yet to hear patrons complaining to a waiter that the wine is screwed.
21. Cheney and Seyfarth 1990.
22. This does seem a little difficult to square with Jarvis’s idea that learned calls are more likely than fixed calls to attract predators.
23. In this case it was the rock star who got the girl.
24. Mithen 2005. I am not entirely convinced. With very few exceptions, people can talk, but very few of us can sing.
25. Deacon 1997, 225.
26. Blowing his own trumpet, so to speak; see http://www.reuters.com/news/video/videoStory?videoId=1231.
27. Kenneally 2007.
28. Pepperberg 2000.
29. This may be a little unfair. Sheldrake and Morgana (2003) have provided a more detailed account in a journal called Journal of Scientific Exploration. You be the judge.
30. Chimps and bonobos shared a common ancestry with humans until six or seven million years ago. Chimps and bonobos split into separate species about two million years ago.
31. Arcadi (2000), who may have overlooked the vocal exchanges between politicians in his analysis.
32. Hayes 1952.
33. Ladygina-Kohts was perhaps the true pioneer of the study of chimpanzee language. She began her work in Moscow in 1913, and continued through the Russian Revolution, publishing her major work in Russian in 1935. The English translation did not appear until 2002.
34. This may seem to contradict the idea that chimp vocalizations can’t be learned. However, chimpanzees do emit a variety of bark sounds, including a pant hoot bark and a waa-bark, so Ladygina-Kohts may have mistaken a natural chimpanzee sound for an imitation.
35. Ladygina-Kohts 2002, 380. It should be said, though, that, Jodi was disadvantaged in ways other than being a chimpanzee. He was emotionally and physically deprived, despite Ladygina-Kohts’s attentions, and died at a young age. He was also a prerevolutionary child, whereas Roodi was born well after the Russian Revolution.
36. The often striking intelligence of dogs may have to do with a long history of domestication by humans.
37. Kaminsky, Call, and Fischer 2004.
38. Savage-Rumbaugh, Shanker, and Taylor 1998.
39. I observe it in myself, too, when in Italy or France, where my level of understanding is not too bad, but I struggle to find the words to make my own contribution to the conversation.
40. If you repeat the word rest, without pausing between repetitions, you may find that it has transmuted into the word stress. It may even transmute further into repetitions of the word ester.
41. Human infants, though, can learn to segregate words at an early age. By about one year of age, they can distinguish function words (like a, the, that, etc.) from content words (Shi, Werker, and Cutler 2006).
42. I am told that this term may now be politically incorrect, and one should call it “parentese.”
43. It might be interesting to insert these words in an otherwise meaningless sentence to see how Kanzi responds.
44. Neidle et al. 2000.
45. In his novel The Thirteen-Gun Salute, Patrick O’Brian assumes the animal was an orangutan.
46. Gardner and Gardner 1969.
47. Patterson 1978.
48. This sounds enigmatic, but “child-side” is the local name for the place in the laboratory where children were studied.
49. Pinker 1994, 340.
50. Kanzi has since coauthored an article, along with two of his relatives, Panbanisha and Nyota (Savage-Rumbaugh et al. 2007). The corresponding author, though, is Sue Savage-Rumbaugh.
51. Miles 1990.
52. Herman, Richards, and Wolz 1984.
53. Pepperberg 1990.
54. Bickerton 1995.
55. Premack 1988.
56. Jackendoff 2002. The implication behind protolanguage is that language emerged in a single step from that point, consistent with “big bang” theories of language evolution. Evidence on grammaticalization, discussed in the previous chapter, suggests that grammatical language evolved gradually. To my mind, this casts doubt on the notion of protolanguage.
57. Köhler 1925.
58. To argue that communicative gestures are a form of problem solving is not to deny them a role in the evolution of language. Problem solving may be indeed have sown the seeds for the later emergence of syntax.
59. Tomasello 1999.
60. Povinelli 2001.
61. Whiten, Horner, and de Waal 2005.
62. Tanner and Byrne 1996.
63. Tomasello et al. 1997.
64. Pollick and de Waal 2007.
65. For gorillas see Pika, Liebal, and Tomasello 2003, chimpanzees see Liebal, Call, and Tomasello 2004, and bonobos see Pika, Liebal, and Tomasello 2005. See also Arbib, Liebal, and Pika 2008 for a discussion of these matters, especially in relation to the origins of language.
66. Chomsky 1966, 78.
67. Hauser, Chomsky, and Fitch 2002.
68. Terminology can be confusing. As far as I can tell, FLN, I-language, and universal grammar all refer to essentially the same thing. The distinction between FLB and FLN seems a remarkably clumsy way of saying that human and animal language overlap in some respects but not in others.
69. Hauser, Chomsky, and Fitch 2002, 1571.
70. Why starlings? Perhaps the authors of this study were inspired by Henry IV, where Shakespeare has Hotspur say
Nay,
I’ll have a starling be taught to speak
Nothing but “Mortimer,” and give it him
To keep his anger still in motion.
71. Gentner et al. 2006. This article was published in the prestigious journal Nature, and soon attracted attention in the media. The experiment was actually based on an earlier one by Fitch and Hauser (2004), in which tamarins proved unable to discriminate the embedded sequences. These authors made no claim that the test had anything to do with recursion as such, but rather compared the animals’ ability to distinguish a finite-state grammar (repeated pairs) from a phrase-structure grammar (embedded pairs), but they appear to accept that the phrase-structure grammar could be parsed by comparing strings of successive elements. To my mind, this somewhat trivializes their study, although it does make a technical point.
72. See, for example, Thompson 1969.
73. I have explained all this more fully in Corballis 2007b. The original article on tamarins was published in Science, and the later article on starlings by Nature, but neither of these eminent journals would accept a critical commentary. I regard the technique used by the authors as a scientific virus that needs to be eradicated. The technique has also been picked up by researchers using brain imaging to find the spot in the brain responsible for recursive parsing (Bahlmann, Gunter, and Friederici 2006; Friederici et al. 2006), but needless to say such endeavors are doomed to likely failure, and your intrepid author has been quick to pounce on this as well (Corballis 2007a).
CHAPTER 4
How Language Evolved from Hand to Mouth
1. Chomsky 2010, 58.
2. Bickerton 1995, 69. He has since modified his view somewhat, arguing that the roots of syntax might be traced to reciprocal altruism in primates, but he still appears to maintain that language in the genus Homo was essentially protolanguage, without syntax, until the emergence of Homo sapiens (Calvin and Bickerton 2000). More recently still, Bickerton (2010) outlines a scenario whereby language evolved more gradually during the Pleistocene.
3. Klein 2008, 271. The nature and implications of the archeological record are discussed more fully in chapter 12.
4. Crow (2010) goes so far as to locate the genetic basis of human speciation in a particular gene pair, Protocadherin11XY, located in homologous regions of the X and Y chromosomes. According to this account, Prometheus was indeed a male, since the critical event occurred on the Y chromosome. Crow suggests that this event occurred within the past 200,000 to 150,000 years, and was the basis of human speciation.
5. Pinker and Bloom 1990, 708.
6. Pinker and Bloom 1990, 711.
7. Ploog (2002) shows how the neural basis for vocalization in humans differs from that in nonhuman primates.
8. Condillac 1971.
9. Condillac 1971, 172.
10. Condillac 1971, 174.
11. Condillac 1971, 175—176.
12. Darwin 1896, 87; emphasis added.
13. Wundt 1900.
14. Critchley 1975, 221.
15. Klima and Bellugi 1979; Poizner, Klima, and Bellugi 1987. Some are still resistant to the idea that signed languages are true languages. At a recent conference I presented the gestural theory, only to be told by a prominent linguist that signed languages were merely pantomime.
16. Two more recent books continue the trend. One is Armstrong and Wilcox’s (2007) book The Gestural Origin of Language, and the other Rizzolatti and Sinigaglia’s (2006) Mirrors in the Brain, which is built on the discovery of mirror neurons.
17. Ramachandran 2000.
18. Arbib and Rizzolatti 1997; Rizzolatti and Arbib 1998.
19. Binkofski and Buccino 2004.
20. As an aside, so to speak, it is worth mentioning here that the system in humans is generally biased to the left side of the brain. For some speculation about this, see Corballis 2004a.
21. Rizzolatti, Fogassi, and Gallese 2001.
22. Dick et al. 2001.
23. Arbib 2005; 2010. Grodzinsky (2006) has expressed reservations about the role of mirror neurons in language.
24. Liberman et al. 1967. It should be noted, though, that the motor theory of speech perception is still controversial after more than 40 years, as is the role of mirror neurons—see Hickok 2009 and Lotto, Hickok, and Holt 2009.
25. The perception of phonemes as invariant despite acoustic variation may depend on a region in the left inferior frontal sulcus—an area not far from Broca’s area (Myers et al. 2009).
26. Kohler et al. 2002.
27. Rizzolatti and Sinigaglia 2006.
28. Fadiga et al. 1995.
29. Aziz-Zadeh et al. 2006.
30. Xua et al. 2009.
31. Pettito et al. 2000.
32. Pietrandrea 2002.
33. Emmorey 2002. Although some signs are iconic, signers nevertheless distinguish signs from free pantomime, and aphasia for sign language leaves pantomime unaffected (e.g., Marshall et al. 2004). Signers don’t seem to notice that some signs are iconic and some are not.
34. Pizzuto and Volterra 2000.
35. Burling 1999.
36. Saussure 1977.
37. Pinker 2007.
38. Shintel, Nusbaum, and Okrent 2006. See also Shintel and Nusbaum 2007 for evidence that people respond to pictures more quickly if a spoken sentence describing the picture matches the motion represented in the picture. They match a moving object, such as a galloping horse, more quickly to the sentence if the sentence is spoken quickly, and match a stationary object more quickly if the sentence is spoken relatively slowly.
39. Hockett 1978, 274—275.
40. Frishberg 1975.
41. In Plato’s Cratylus, Socrates asks, “Suppose we had no voice or tongue, and wanted to communicate with one another, should we not, like the deaf and dumb, make signs with the hands and head and rest of the body?”
42. Zeshan 2002.
43. Evans 2009.
44. Pinker 2007.
45. Wood and Collard 1999.
46. Burling 2005, 123.
47. MacNeilage 2008. He is a compatriot of mine, but I’m sure I can bring him round.
48. Rizzolatti et al. 1988.
49. Petrides, Caddoret, and Mackey 2005.
50. Gentilucci et al. 2001. You are advised to try to keep your mouth shut when reaching for a large object, such as a pineapple.
51. See Gentilucci and Corballis 1996 for a review.
52. Bernardis et al. 2008.
53. McGurk and MacDonald 1976. At the time of writing, and I hope still, you can experience the McGurk effect on http://www.youtube.com/watch?v=aFPtc8BVdJk.
54. Calvert and Campbell 2003; Watkins, Strafella, and Paus 2003.
55. The edited volume by Sutton-Spence and Boyes-Braem (2001) spells out systems used in several European signed languages.
56. Emmorey 2002.
57. Muir and Richardson 2005.
58. Studdert-Kennedy 1998.
59. Browman and Goldstein 1995.
60. Vargha-Khadem et al. 1995.
61. Fisher et al. 1998; Lai et al. 2001.
62. Corballis 2004a.
63. Liégeois et al. 2003.
64. Haesler et al. 2007.
65. Groszer et al. 2008.
66. Enard et al. 2009. The vast congregation of authors suggests that the effect may be due to alterations in circuits linking the cortex to the basal ganglia. This may have some bearing on the manner in which vocalization was brought under cortical control in humans.
67. Enard et al. 2002.
68. Now deceased.
69. Krause et al. 2007.
70. Coop et al. 2008.
71. Evans et al. 2006.
72. Some of them evidently had red hair and fair complexions (Culotta 2007). Make of that what you will. Recent evidence from sequencing the Neandertal genome strongly suggests that the ancestors of non-Africans probably did mate with Neandertals, so there was some limited exchange of DNA (Green et al. 2010).
73. Schroeder and Myers 2008.
74. See Fisher and Scharff 2009 for a recent review.
75. P. Lieberman 1998; Lieberman, Crelin, and Klatt 1972.
76. Noonan et al. 2006.
77. See, for example, Boë et al. (2002; 2007), who argue, contrary to Lieberman, that the vocal apparatus of the Neandertals would indeed have permitted articulate speech, although his arguments have been questioned in turn by de Boer and Fitch (2010). Boë et al. (2007) also suggest that any restrictions on articulation, in human infants as in Neandertals, may have been due to imprecise motor control of the articulators rather than to the shape of the vocal tract.
78. Tattersall 2002, 167. See also previous note.
79. D. E. Lieberman 1998.
80. Lieberman, McBratney, and Krovitz 2002.
81. In other words, our foreheads are kind of bulbous.
82. Kay, Cartmill, and Barlow 1998.
83. DeGusta, Gilbert, and Turner 1999.
84. MacLarnon and Hewitt 2004.
85. P. Lieberman 2007, 39. Robert McCarthy of Florida Atlantic University has recently simulated how the Neandertal would have sounded when articulating the syllable /i/ (or ee), based on the shape of the vocal tract. It can be found on http://anthropology.net/2008/04/16/reconstructing-neandertal-vocalizations/, and compared with a human articulating the same sound. One observer described the Neandertal’s attempt as sounding more like a sheep or a goat than a human. But see Boë et al. 2002 for contrary evidence.
86. Konner 1982.
87. Kingsley 1965, 504.
88. The eloquent Italians, for example, gesture more than we undemonstrative Kiwis do.
89. Russell, Cerny, and Stathopoulos 1998.
90. Evans 2009.
91. An even more parsimonious system is Silbo Gomero, a whistled language used by shepherds on the island of Gomero in the Canary Islands, which is reduced to two vowels and four consonants. It is perhaps an unfair example, though, because it is essentially a cut-down version of Spanish (Carreiras et al. 2005).
92. Everett 2005.
93. Salmond 1975, 50.
94. It depends on how the analysis is done (Evans 2009).
95. Saying it backwards probably helps a bit.
96. The commonly expressed idea that infants can discriminate phonemes of all the world’s languages (“Universal Theory”) has been challenged by Nittrouer (2001), but defended by Aslin, Werker, and Morgan (2002).
97. Darwin 1896, 89.
98. The cooking of food, not televisions, although given the explosive language of some TV chefs one might wonder.
99. Corballis 2002.
100. McNeill 1992; Goldin-Meadow and McNeill 1999.
101. Wittgenstein 2005.
PART 2
Mental Time Travel
1. Hockett 1960.
CHAPTER 5
Reliving the Past
1. Forster 1995, 133—134.
2. Bruce, Dolan, and Phillips-Grant 2000.
3. The distinction between episodic and semantic memory was developed by the Canadian psychologist Endel Tulving (1983; 2002).
4. That is as I remember it, of course. Others in the class may remember it differently.
5. See, for example, Tulving et al. 1988.
6. Tulving 2002.
7. Burianova and Grady (2007) examined brain activation, using functional magnetic brain imaging (fMRI), while people retrieved autobiographical, episodic, and semantic memories. There was considerable overlap, suggesting common processes, but each kind of memory also elicited unique activation. Autobiographical retrieval triggered unique activation in the medial frontal lobe, which is probably associated with representation of the self. Episodic retrieval uniquely activated the right middle frontal lobe and semantic retrieval the right inferior temporal lobe.
8. Wearing 2005.
9. Short-term memory, also known as working memory, holds information in consciousness for a few seconds, and is distinct from the semantic and episodic systems that make up long-term memory.
10. This case was first described by Scoville and Milner (1957). For a more recent account, see Corkin 2002.
11. This theory was developed by Larry Squire and colleagues (e.g., Squire 1992), but other models of hippocampal function have been suggested (e.g., Moscovitch et al. 2006).
12. See Tulving 2002 for a review.
13. Tulving 2001.
14. Hodges and Graham 2001.
15. Mitchell 2006.
16. Loftus and Loftus 1980.
17. But not necessarily sober.
18. Kundera 2002, 122—123.
19. Treffert and Christensen 2006.
20. Luria 1968, 22.
21. Parker, Cahill, and McGaugh 2006.
22. Pinker 2007 bases this estimate on the number of words in a desk (i.e., not an unabridged) dictionary.
23. Loftus and Ketcham 1994, 39.
24. Roediger and McDermott 1995.
25. Burnham 1989.
26. Bernheim 1989, 164—165.
27. In later editions of the book (e.g., 1994), Bass and Davis qualified their statement, indicating that symptoms of distress need not imply abuse. The hysteria over sexual abuse has largely abated since the 1990s, although there are undoubtedly still many innocent individuals whose lives were wrecked because of false accusations arising from falsely recovered memories.
28. The question of whether a memory is true or false is a classic one in a branch of science known as signal detection theory. Memory is often a weak signal, and one can be as uncertain of whether a memory is real or not as of whether a noise in the house is an intruder or not, or whether a pain in one’s chest is a signal of an impending heart attack. Where a signal is weak, there are two kinds of error one can make: one can fail to detect a signal that is truly there, or one can falsely detect a signal that is not there. If we apply that understanding to the question of memory for sexual abuse, one can suppose that abuse did not occur when in fact it did, or one can suppose that it did occur when it did not. Each error carries a cost. Failure to detect past abuse may leave a perpetrator free to continue to abuse, while false detection can result in innocent people being punished. Much of the political argument boils down to the question of which of these errors is the more costly. Many feminists appear to believe that it is better that some innocent people be sent to jail than to have perpetrators of abuse at liberty, while the basic legal tenet that one is innocent until proven guilty protects the innocent at the expense of failing to detect actual perpetrators. Judgments may be biased toward the former by aggressive therapy leading to implantation of false memories.
29. Hood 2001.
30. Pinker 1994.
31. The story of Genie and other so-called wild children is told in Newton 2004.
32. Pavlov 1927. Classical conditioning featured as a major theme in Aldous Huxley’s Brave New World.
33. In the politically correct terminology of modern experimental psychology, the term “participant” is preferred to “subject.” In this particular case, the term “subject” seems altogether more appropriate.
34. Watson and Rayner 1920.
35. Skinner 1957.
36. Skinner 1962. The title derives from Thoreau’s Walden.
37. It was a word I had only recently discovered, and I rather liked the sound of it. I really didn’t know what it meant.
CHAPTER 6
About Time
1. Suddendorf and Corballis 1997; 2007.
2. Atance and O’Neill 2005. Suddendorf (2010) also suggests the term “episodic foresight.”
3. See also Busby Grant and Suddendorf 2009.
4. Atance and O’Neill 2005; Klein, Loftus, and Kihlstrom 2002.
5. Ingvar 1979, 21.
6. Schacter, Addis, and Buckner 2007.
7. Addis, Wong, and Schacter 2007; Okuda et al. 2003; Szpunar, Watson, and McDermott 2007.
8. Botzung, Denkova, and Manning 2008; D’Argembeau et al. 2008; Hassabis, Kumaran, and Maguire 2007.
9. The constructive nature of episodic memory was classically demonstrated by the British psychologist Sir Frederic C. Bartlett (1932).
10. Suddendorf and Corballis 1997; 2007.
11. Köhler 1925.
12. See, for example, Kamil and Balda 1985.
13. This inspired term was proposed by Suddendorf and Busby (2003).
14. Clayton, Bussey, and Dickinson 2003.
15. Dally, Emery, and Clayton 2006.
16. Ferkin et al. 2008.
17. Roberts et al. 2008.
18. Bischof 1978; Bischof-Köhler 1985; Suddendorf and Corballis 1997.
19. Correia, Dickinson, and Clayton 2007.
20. See Suddendorf, Corballis, and Collier-Baker 2009 for a critique of this and other studies purporting to refute the Bischof-Köhler hypothesis.
21. McGrew 2010.
22. Hunt and Gray 2003.
23. This is the consensus of Whiten and eight coauthors (1999). See also Whiten, Horner, and de Waal 2005.
24. Boesch and Boesch 1990.
25. Mulcahy and Call 2006. Curiously, though, bonobos, like gorillas, show little evidence of tool use in the wild (McGrew 2010).
26. See Suddendorf 2006 for a critique.
27. Bang on.
28. It has been suggested that the linear concept of time did not emerge until late antiquity, and that earlier understanding was cyclical (Butterfield 1981).
29. Everett 2005.
30. Pettit 2002.
31. Andrews and Stringer 1993.
32. Markus and Nurius 1986.
33. James 1910.
34. Markus and Nurius 1986, 954.
35. Neisser 2008, 88.
CHAPTER 7
The Grammar of Time
1. From a conversation with Freddy Gray, reported in The Spectator of 10 April 2010.
2. Pinker 2003, 27.
3. Yes, I know—even this book is something of a just-so story.
4. Hebb had a distinctly mediocre undergraduate record, and his initial intention was to become a novelist.
5. See also Corballis and Suddendorf 2007.
6. Tulving 2002.
7. Pinker 2007. As I mentioned before, this estimate is based on the number of words in a common dictionary.
8. Deacon 1997.
9. Liszkowski et al. 2009.
10. Lin 2006. Aspectual markers are formally distinguished from tense, and have to do with the temporal flow rather than the location in time. In English, for example, the sentences “I talk” and “I am talking” are both present tense, but are distinguished by aspect, with the first representing a habitual activity and the second a progressive or continuous one.
11. It’s time I got this damn book written.
12. Reichenbach 1947.
13. Núñez and Sweetser 2006.
14. Chen 2007.
15. Everett 2005. It should be said that Everett’s analysis is controversial, as evident in the commentaries following his article. Yet he and his family are the only outsiders who know the language of the Pirahã, and are best equipped to pronounce on its properties, at least to those who don’t speak it.
16. In some respects Everett is not entirely consistent. For instance he does note that the Pirahã are “afraid of evil spirits” (2005, 623). To the Western eye, evil spirits might well be seen as fictitious, although perhaps to the Pirahã they are seen as part of everyday reality. Again, Everett states that “Pirahã repeat and embellish these stories” (633), but the claim is that the stories are based on firsthand experience, and are not fictional.
17. Everett 2005, 632.
18. Whorf 1956, 57—58.
19. Malotki 1983. It may well be that Everett also underestimated the Pirahã sense of time.
20. They should be so lucky.
21. Skinner 1957.
22. Westen 1997, 530. Nevertheless Skinner was interested in psychoanalysis, and even wanted to be psychoanalyzed—but was turned down! (Overskeid 2007).
23. This was the main theme of Chomsky’s famous 1959 review of Skinner’s 1957 book Verbal Behavior.
24. Frege 1980, 79. To most linguists, though, words are but a step in the hierarchy that proceeds from phonemes to morphemes to words. As we saw in chapter 2, though, words may be the true primitives in an evolutionary sense, with phonology and morphology emerging as a result of pressure to create distinctions (Aronoff 2007).
25. Horne Tooke 1857. Objects are represented by nouns and actions by verbs. Technically, though, the object/action distinction is not the same as the noun/verb distinction. Many nouns (such as love or coherence) do not represent objects, and many verbs (such as enjoy or wonder) do not represent actions. The idea that the first words were nouns and verbs actually goes back to Plato.
26. In case you’re traveling this year, they are Warao in Venezuela, Nadëb in Brazil, Wik Ngathana in northeastern Australia, and Tobati in West Papua New Guinea.
27. Aronoff et al. 2008.
28. A curious exception is C. P. Snow’s last novel, A Coat of Varnish, published in 1979. The murderer is never revealed.
29. It can go the other way. The 1994 movie Heavenly Creatures, directed by Peter Jackson, is based on the true story of two New Zealand schoolgirls who murdered the mother of one of them. They were of course caught, and one of them is now an internationally known author of murder stories.
30. Maybe we should add quarks and leptons and bosons, and the other entities postulated by modern theoretical physics.
31. Wilson 2002, 64.
32. Boyd 2009.
33. There must surely be limits to this. Science depends on the discovery of truth and, one may hope, is adaptive. This adaptiveness may be foiled by belief in falsehood.
34. Or so I believe, God help me.
35. Boyd 2009, 206.
CHAPTER 8
Mind Reading
1. Randi 1982. The James Randi Educational Foundation was established in 1996 to further Randi’s work. It offers a large monetary prize to anyone who can demonstrate psychic powers. As of 10 July 2007 this long-standing offer remains unclaimed, and the award stands at $1,000,000. See www.randi.org for updates.
2. Marks and Kammann 1980.
3. Sheldrake 1999. Once again, the intrepid David Marks has struck, in the new edition of his earlier book with Kammann (Marks 2000). One wonders if Sheldrake saw it coming.
4. Darwin 1872, 357—a long quote, to be sure, but the image of Darwin pulling faces and trying to look savage is too much to resist.
5. Piaget 1928.
6. Borke 1975. One might have thought, though, that mountains would have been pretty familiar to Swiss children.
7. Southgate, Senju, and Csibra 2007. The authors included a familiarization phase to ensure that the infants would look to where the actor would retrieve a ball when it was actually present, as well as variations to rule out other possibilities, such as the infants simply looking to where the ball was most recently placed.
8. I suppose the catwalk might make you wonder, although those young women seem scarcely built for reproduction.
9. Cosmides and Tooby 1992.
10. Trivers 1974.
11. Barkow, Cosmides, and Tooby 1992.
12. The term was inspired by Franz B. M. de Waal, whose 1982 book Chimpanzee Politics noted that some of the social strategies used by chimpanzees had a Machiavellian flavor. Much has been written on the question of whether chimpanzees and other primates are truly Machiavellian, or possess what has been termed “theory of mind”—the ability to take on the mental perspectives of others (e.g., Byrne and Whiten 1990; Premack and Woodruff 1978; Tomasello and Call 1997; Whiten and Byrne 1988). Whatever the case with respect to other primates, it seems that we humans are supreme in our ability to lie, cheat, and deceive, while also maintaining outward respectability.
13. Dennett 1983.
14. Cargile 1970.
15. Dunbar 2004, 185.
16. Fifth-order recursion may be necessary for religious belief, but is surely not sufficient. I think I am capable of this order of recursion, but I am not religious. I can’t answer for Robin Dunbar.
17. Baron-Cohen 1995.
18. Grandin 1996; Grandin and Barron 2005; Grandin and Scariano 1986. Grandin would now be classified as a case of Asperger’s syndrome, which is a form of autism in which intellectual function is high.
19. Sacks 1995.
20. Grandin and Johnson 2005.
21. Senju et al. 2009.
22. Crespi and Badcock 2008.
23. Actually best known for his involvement in the antipsychiatry movement.
24. Hamilton 2005, 205.
25. Baron-Cohen 2002.
26. See Crespi and Badcock 2008 for a more detailed account.
27. See Crespi and Badcock 2008, 248, for more extensive lists. This account, though, is not uncontroversial, since some psychiatrists regard schizophrenia and autism as related, rather than as polar opposites. Both show very similar patterns of brain activation (Pinkham et al. 2008). One possibility is that the negative symptoms of schizophrenia join autism at one end of the spectrum, with positive symptoms of schizophrenia at the other (van Rijn, Swaab, and Aleman 2008). Recent evidence implicates genetic influences in both autism (no fewer than three papers on this appear in the 28 May 2009 issue of Nature) and schizophrenia (e.g., Esslinger et al. 2009), with no indication that imprinting plays a role. Even so, Crespi and Badcock present an interesting scenario with implications beyond autism and schizophrenia.
28. Badcock and Crespi 2006.
29. Baron-Cohen 2009.
30. The reader should appreciate that the distinction between people people and things people is bound to be somewhat simplistic.
31. Maudsley 1873, 64.
32. Kéri 2009. The gene in question is Neuregulin 1, and the particular genotype is T/T.
33. Horrobin 2003. See Richmond 2003 for a perspective on David Horrobin.
34. Farmelo 2009. In Bristol, UK, Dirac’s reputation is overshadowed by that of his schoolmate Archie Leach, better known later as Cary Grant.
35. Langford et al. 2006.
36. Wechkin, Masserman, and Terris 1964.
37. de Waal 2008.
38. See Povinelli, Bering, and Giambrone 2000 for a summary.
39. Tomasello, Hare, and Agnetta 1999.
40. Povinelli and Bering 2002.
41. Hare et al. 2000. Marmosets also choose food that a watching dominant marmoset can’t see (Burkart & Heschl, 2007).
42. Hare, Call, and Tomasello 2001.
43. Hare, Call, and Tomasello 2006.
44. Hare and Tomasello 1999.
45. The cleverness of dogs has become a matter of some contention. The apparent ability of domestic dogs to read human intentions has been attributed to selective breeding, and may be rather more restrictive than is at first apparent. Dogs have been bred to collaborate with people, but they don’t seem to collaborate with other dogs. For a useful discussion, see Morell 2009.
46. For a detailed critique of Hare’s studies, and of others studies claiming theory of mind in corvids, see Penn, Holyoak, and Povinelli 2008.
47. Whiten and Byrne 1988.
48. Leslie 1994; Tomasello and Rakoczy 2003.
49. Leslie (1994) has referred to these levels of attribution as ToMM-1 (Theory of Mind Module 1), involving attribution of goal-directedness and self-generated motion, and ToMM-2 (Theory of Mind Module 2), involving full-blown theory of mind. Hauser and Carey (1998) remark that “the intellectual tie breaker between humans and nonhumans is likely to lie within the power of ToMM-2.”
50. Gallup 1998.
51. For review, see Suddendorf and Collier-Baker 2009.
52. Penn, Holyoak, and Povinelli 2008, 129.
53. No doubt having in mind, as it were, the onetime preeminence of the RollsRoyce automobile manufacturing company.
CHAPTER 9
Language and Mind
1. Fodor 1975.
2. Pinker 2007, 90.
3. For the benefit of U.S. readers, “pissed” here refers to being drunk, and not to being angry. It might be appropriate for newts to describe the occasionally drunken newt as being as pissed as a human.
4. This act has created considerable controversy and argument as to how it should be interpreted. It does seem to permit hunting by women.
5. Watson 1913, 158.
6. Griffin 2001, 1.
7. Inoue and Matsuzawa 2007. The chimps first learned to recognize the digits 1 through 9, and to point to them in succession when they were randomly displayed on a console. In one memory test, five digits were randomly selected and displayed in random positions and then blanked out and replaced with white squares. One chimp, Ayumu, maintained 80 percent accuracy when the duration of the digits was reduced to a mere fifth of a second, a performance well above that reached by a group of university students.
8. Pinker 2007, 23.
9. Fauconnier 2003, 540.
10. Grice 1989, 30—31. If you’re not used to minding your philosophical Ps and Qs, you could take as an example P = “Hello, John, this is a surprise. How were they?” and Q = This is my friend John, who must be back early from Australia, where he went to visit his aging parents.
11. Sperber and Wilson 2002, 15.
12. Sperber and Wilson 1986.
13. The term “minimalism” is more often used with respect to a school of music, in which the work is stripped down to its basic features.
14. Grice 1975.
15. Language deficits can be identified in infants as young as two, and are manifest in poor imitation and gestural communication (Luyster et al. 2008).
16. Irony may be culturally specific, despite Kierkegaard’s claim. Tom Suddendorf, a native of Germany, tells me that Germans don’t need it—and even if they did, they wouldn’t get it. He may have been being ironic.
17. Perhaps the only example of a double positive translating as a negative.
18. Dostoevsky 2008.
19. Gibbs 2000.
20. Papp 2006. GCSE stands for General Certificate of Secondary Education, a qualification sought by 12- to 14-year-old children in England, Wales, and Northern Ireland (but not Scotland). It can be taken in several subjects, but only once.
21. Happé 1995.
22. As an addict of cryptic crosswords, I often need to assume the somewhat autistic mentality of the compiler. One normally assumes the word number, for example, has to do with counting, but in crosswords it often refers to anesthetic. And don’t be fooled by the word flower, which can be synonymous with river. Or layer, which can refer to a hen.
23. Walenski et al. 2008.
24. Hauser, Chomsky, and Fitch 2002.
25. Tomasello 2008.
26. One wonders, though, why they can point at all, since for most of their evolutionary existence they have not had to put up with the company of humans.
27. Tomasello 2008, 55.
28. Rivas 2005.
29. Greenfield and Savage-Rumbaugh 1990.
30. I am sharing this information with you, and don’t expect any reward. It would be nice, though, if you would consider buying the book, if you haven’t done so already.
31. The sex of the child is not stated, but I am assuming she is female. My assumption is based on the fact that I have a granddaughter. This is also information I’d like to share with you. Note added in 2010: I now have three granddaughters.
32. But how would you know?
33. de Villiers (2009) provides a useful discussion of the joint emergence of language and theory of mind, and the interface between them.
CHAPTER 10
The Recurring Question
1. From Pensées 1670.
2. Walsh et al. 2003.
3. Johnson 2000.
4. Australia is a great slab of a place to the west and somewhat to the north of New Zealand.
5. Sosis 2004.
6. Bloom (2004) is not the only one to suggest that dualism is innate. See also Shermer’s Why People Believe Weird Things (1997), and Hood’s Why We Believe the Unbelievable (2009).
7. Dennett 1995.
8. Dobzhansky 1973, 125.
9. See “Shunning the E-word in Georgia,” Science, 303, 759 (2004).
10. This is not to say that all religions support the idea. Writing in the 18 January 2005 issue of L’Osservatore Romano, the official Vatican paper, Fiorenzo Facchini argued that intelligent design belongs to the realms of philosophy and religion, but not of science. He writes that “it is not correct from a methodological point of view to stray away from the field of science while pretending to do science.” The Vatican has for many years tolerated the teaching of evolutionary theories, and in 1950 a papal encyclical officially permitted Catholics to discuss Darwin’s theory of evolution. In another development, on 20 December 2005 federal district court judge John Jones III ordered the schools in Dover, Pennsylvania, to remove references to intelligent design from the science curriculum, on the grounds that it is not science.
11. As reported in Time magazine, 15 August 2005, 47.
12. Davis and Kenyon 2004, 99—100.
13. I am told the octopus eye is better designed, with the optic nerve located at the back of the retina.
14. Not everyone believes this, but few of the dissenters are willing to attribute the plays to an ape. The poems, maybe, but not the plays.
15. Cited by Darwin 1896, 49.
16. Quoted in Marchant 1916, 241.
17. Gross 1993.
18. A word that itself gives the game away.
19. And for insects, of course. To put it another way, they took hold of an idea and flew with it.
20. Chomsky 1966.
CHAPTER 11
Becoming Human
1. Until fairly recently, the term hominid was used, but the great apes were invited to join the hominid clade when it was discovered just how closely their genetic makeup resembled our own. See also Note 33 in chapter 2.
2. That is, if we discount the role of horses, mules, carriages, bicycles, scooters, automobiles, trains, ships, airplanes, and space rockets. Oh, and swimming, I suppose—but you get what I mean.
3. Brunet et al. 2002.
4. Sibley and Ahlquist 1984. There is nevertheless still some uncertainty and conflicting evidence about the ape-hominin split. One recent theory, based on analysis of diversity of differences across the genome, is that the hominin and chimpanzee lineages split close to seven million years ago, but then hybridized, finally splitting again within the past 6.3 million years (Patterson et al. 2006).
5. Galik et al. 2004.
6. Leakey 1979.
7. Thorpe, Holder, and Crompton 2007.
8. Lovejoy et al. 2009.
9. Quoted in Gibbons 2009, 39.
10. These developments may help destroy the idea that the chimp somehow failed to move on from common ancestry with humans some six million years ago, and is therefore a sort of failed human. Chimpanzee evolution simply took a different path.
11. Teleki 1973.
12. Bipedalism is a pain in the ass.
13. Formerly known as Ayer’s Rock.
14. I am indebted to the useful discussion in chapter 12 of Michael Sims’s 2003 book Adam’s Navel.
15. Darwin 1872, 138.
16. Quoted in Isaac 1992, 58.
17. As I write, though, it looks as though the Australian cricketers may lose the Ashes series against England. Note added later: They did. Note added even later (2006/2007): Then they lost to them again. Now (late 2010) they look like losing again.
18. Calvin 1983.
19. Kirschmann 1999.
20. In that game, they actually don’t seem to throw the ball, but sort of paddle it with the hand. But they kick the ball a lot, and kicking in this fashion, also done in rugby, itself requires a bipedal stance. As a New Zealander, I am tempted to think that pressure to kick a rugby ball was a factor in the evolution of bipedalism, but to my knowledge there is no evidence for rugby pitches dating from six million years ago, and in any event we had to wait for the Neandertals to evolve before we could pack a decent scrum.
21. Bowlers in cricket, for some obscure reason, are not allowed to flex the elbow, and compensate by running up to the bowling crease, thereby building up kinetic energy, before releasing the ball.
22. Bowling in cricket is again an exception, since fast bowlers build up speed before releasing the ball.
23. Marzke 1996.
24. Bronowski 1974, 115—116. Aristotle credited the Greek philosopher Anaxagoras with the view that it is because of the hands that humans are the wisest animal.
25. Young 2003.
26. Alemseged et al. 2006.
27. Westergaard et al. 2000.
28. Darwin 1896, 82.
29. Toth et al. 1993.
30. Bingham 1999.
31. Shaw 1948, 195.
32. The vote was taken in May 2009 by a committee of the International Commission on Stratigraphy (ICS)—see Kerr 2009.
33. Wood and Collard 1999.
34. Berger et al. 2010; Dirks et al. 2010.
35. Other members of the genus have been identified, but it depends a bit where you draw the lines of demarcation. That little group will do for now.
36. Foley 1984.
37. Bramble and Lieberman 2004.
38. Richard William Pearse, a New Zealand famer, is said to have taken to the air in a heavier-than-air machine on 31 March 1903, some nine months before the Wright brothers. The evidence on this, though, is still up in the air.
39. Darwin 1896, 64.
40. Hrdy 2009.
41. Another possibility would have been flight, but that was for the birds.
42. Tooby and DeVore 1987. An alternative view is that the third way did not arrive until Mr. Tony Blair was elected Prime Minister of Great Britain.
43. Humphrey 1976.
44. Alexander 1990, 4.
45. Wrangham 2009.
46. Goren-Inbar et al. 2004.
47. Or so it is said. Perhaps it applies especially to mammals, since crocodiles have very small brains, as did the dinosaurs.
48. They are bipedal, they fly, they learn complex vocal sequences, they make tools, and, as we saw in chapter 6, it has been claimed that they travel mentally in time.
49. Jerison 1973. The formula is EQ = (brainweight) / (.12 × bodyweight.66). It is calibrated so that the EQ of the average mammal is 1.0, and the exponent of 0.66 compensates for the tendency of brain size to increase at a slower rate than body weight.
50. Every decimal point counts, it seems.
51. Dunbar 1993.
52. Her remains were discovered in 1976 by Donald Johanson and colleagues in Ethiopia, and named after the Beatles’ song “Lucy in the Sky with Diamonds.” Whether Lucy had ever used LSD is unknown. See Johanson and Edey 1981.
53. These figures are from Martin 1992.
54. Noonan et al. 2006.
55. Evans et al. 2004.
56. Mekel-Bobrov et al. 2005.
57. Evans et al. 2006.
58. For review, see Dorus et al. 2004.
59. In case you ask, the enzyme is called CMP-N-acetylneuraminic acid (CMPNeu5Ac) hydroxylase (CMAH). The inactivating mutation of this gene has resulted in the absence in humans of the mammalian sialic acid N-glycolylneuraminic acid (Neu5Gc). This work is described by Chou et al. (2002).
60. Stedman et al. 2004.
61. Currie 2004.
62. It pains me to report that there is now some doubt as to the role of MYH16 in the increase in brain size—see McCollom et al. 2006.
63. Pinker 1994.
64. Actually, I don’t really think it’s a good idea to be rid of taxes, which have supported me throughout my academic life.
65. Deacon 1997.
66. Semendeferi, Damasio, and Frank (1997) showed that the ratio of the frontal lobes to the rest of the brain is constant in apes and humans, while Uylings (1990) suggests that the ratio has changed little from rats to humans. Deacon (1997, 476) is critical of these studies, partly on the grounds that they do not measure the prefrontal cortex independently of motor and premotor areas. A more recent study suggests that the volume of white matter in the prefrontal cortex is disproportionately large in humans relative to other primates, but the volume of grey matter is not (Schoenemann, Sheehan, and Glotzer 2005). Maybe white matter is what matters.
67. Flinn, Geary, and Ward 2005.
68. Dr. Darwin, that is.
69. Locke and Bogin 2006.
70. Locke and Bogin 2006, 262.
71. Busby Grant and Suddendorf 2009.
72. This is not to say that humans don’t migrate seasonally. Wealthy Canadians migrate to Florida or Hawaii during the winter, and New Zealanders fly off to Queensland in Australia.
73. Anton 2002. One delightful exception is the hobbit-like hominin known as the Lady of Flora—or more formally as Homo floresiensis—whose skeleton remains were discovered on the island of Flora in Southeast Asia (Brown et al. 2004). She appears to date from a mere 18,000 years ago, which is by far the most recent date for any hominin who does not belong to our own species, Homo sapiens. An adult, she was only about one meter tall, with a brain volume of only about 380 cc, which is rather smaller than that of a modern chimpanzee. Her encephalization quotient (EQ) was nevertheless within the range 2.5—4.6, which compares with that of Homo erectus at between 3.3 and 4.4. The current consensus seems to be that she belonged indeed to the species Homo erectus (e.g., Falk et al. 2005), but had been subjected to what is known as “insular dwarfism” arising from long-term isolation and limited resources. As a New Zealander, I worry that the same thing might occur on our own islands and affect our rugby team—hobbits have already been detected in some areas.
74. Dennell and Roebroeks 2005.
75. Bogart and Pruetz 2008.
76. Pruetz and Bertolani 2007.
77. Boesch, Head, and Robbins 2009. The tools are identified as pounders, enlargers, collectors, perforators, and swabbers. They are mindful of the tools used in modern surgery.
78. Carvalho et al. 2009.
79. Sousa, Biro, and Matsuzawa 2009.
80. Beck 1980, 218.
81. Semaw et al. 1997.
82. Chazan et al. 2008.
83. Hunt 2000. These birds also shape twigs to act as hooks (Weir, Chappell, and Kacelnik 2002).
84. Walter et al. 2000.
85. Hoffecker 2007.
86. Noonan et al. 2006.
87. No one seems to have suggested that the horses made the spears.
88. Thieme 1997.
CHAPTER 12
Becoming Modern
1. As remarked in note 72 in chapter 4, it has become fairly apparent that Homo sapiens mated with the Neandertals some time after the migration from Africa, but before the Asian and European populations split—some 50,000 to 80,000 years ago. The estimated gene flow from Neandertal to non-African H. sapiens is estimated at between 1 and 4 percent (Green et al. 2010).
2. Atkinson, Gray, and Drummond 2009. Four other haplotypes have also been identified but these are rare.
3. Cann, Stoneking, and Wilson 1987. Tracing mtDNA back to a single woman does not mean that Mitochondrial Eve was the only woman alive at the time.
4. Atkinson, Gray, and Drummond 2008.
5. Mellars 2006a.
6. Brown et al. 2009. These authors suggest that the technological use of fire at Pinnacle Point in South Africa may go back as far as 164,000 years ago.
7. Goren-Inbar et al. 2004.
8. Henshilwood et al. 2002.
9. Mellars 2006b.
10. Carto et al. 2009.
11. Bowler et al. 2003.
12. Marean et al. 2007.
13. Mellars 2006a.
14. Crow 2010—see note 10 in chapter 4.
15. Hoffecker 2005, 195; emphasis added.
16. Crystal 1997.
17. Knight et al. 2003.
18. I suggested this in my 2002 book From Hand to Mouth, but that was before I knew about the FOXP2 gene.
19. Especially the Italians.
20. Corballis 2004b.
21. Conard, Malina, and Münzel 2009.
22. Kvavadze et al. 2009.
23. Hoffecker 2005.
24. Conard 2009.
25. Mellars 2009, 177. He doesn’t divulge the student’s sex.
26. Mellars 2005.
27. Darwin 1896, 64.
28. Mellars and Stringer 1989.
29. Klein 2008. Again, of course, a candidate mutation is that of the FOXP2 gene. As we saw in chapter 4, one recent estimate places this mutation at closer to 50,000 years ago than 100,000 years ago (Coop et al. 2008). Nevertheless this remains contentious, especially following evidence that the mutation may have been present in the common ancestor of human and Neandertal (Krause et al. 2007).
30. Powell, Shennan, and Thomas 2009. The estimated date of 45,000 years ago places this very early in the estimated date of migration into Europe, but there still seems to be some uncertainty in the dating of these events.
31. Ambrose 1998.
32. New Zealand is sometimes known as the shaky isles, especially in Australia, and an eruption of Lake Taupo in about AD 280 caused the sky to glow red as far away as Russia and China. It is said to have erupted some 28 times since the original huge eruption around 26,500 years ago, and it could pop again at any time.
33. Arthur 2007, 277.
34. Letter to Robert Hooke, dated 15 February 1676.
35. Although cultural variation is now well documented in chimpanzees, Whiten et al. (2009) suggest that, unlike human culture, chimpanzee culture is not cumulative. The ratchet-like nature of human culture allows it to cumulate over generations. This is perhaps another example of recursion, in which past cultural development is embedded in present culture.
36. Diamond 1997, 14. For “cargo” you can mostly read “junk”—stuff you don’t really need.
CHAPTER 13
Final Thoughts
1. Chapter 13 is entitled “Secondary Sexual Characters of Birds.”
2. Darwin 1896, 126. It is interesting that this passage begins with reference to higher animals and ends with reference to lower ones.
3. Arnold 1992.
4. E.g., Ambrose 2001.
5. There may nevertheless be cultural variation. The Pirahã, discussed in chapters 6 and 7, appear to have a relatively reduced language and sense of time, but may compensate in other ways. There is little question, moreover, that all humans possess the capacity for unlimited expression, but cultures vary to the manner in which that capacity is exploited.
6. Arthur 2007.
7. Dunbar 2004.
8. Me, I am scarcely able to even screw in a lightbulb.
9. Wiles 1995; Taylor and Wiles 1995. There remains the remote possibility that Fermat had a much simpler proof all along.
10. Hamilton 2005.
11. Beyerstein 1999.
12. My mother did try. She took me skiing at the age of 16 (my age, not hers), but conditions were fairly primitive, and after struggling some distance up the mountain I accidently released one ski, which sped all the way down again. I suppose if I had persevered with the remaining ski I might have invented snowboarding.