How 'Intuition' Exploded∗ James Andow August 7, 2014 Abstract Recent decades have seen a surge in interest in metaphilosophy. In particular there has been an interest in philosophical methodology. Various questions have been asked about philosophical methods. Are our methods any good? Can we improve upon them? However, prior to such evaluative and ameliorative concerns, is the matter of what methods philosophers actually use. Worryingly, our understanding of philosophical methodology is impoverished in various respects. I consider one particular respect in which we seem to be missing an important part of the picture. While it is a received wisdom that the word 'intuition' has exploded across analytic philosophy in recent decades, I present evidence that the explosion is apparent across a broad swathe of academia (and perhaps beyond). I note various implications for current methodological debates about the role of intuitions in philosophy. 1 A Received Wisdom Goldman gives voice to a received wisdom in philosophical methodology: . . . philosophers haven't always described their methodology in the language of intuitions. In fact, this seems to be a fairly recent bit of usage. Jaakko Hintikka (1999) traces the philosophical use of 'intuition' to Chomsky's description of linguistics' methodology. In the history of philosophy, and even in the early years of analytic philosophy, the terminology is not to be found . . . This is not to say that historical philosophers and earlier 20th-century philosophers did not make [appeals to intuition], they just didn't use the term 'intuition' to describe them. (Goldman, 2007, 2) This wisdom is that, regardless of whether the methods of analytic philosophy have changed in recent decades, the terminology has. Philosophers use words like 'intuition' a lot and they only started doing this recently. The reason many accept this picture may owe much to Hintikka (1999), but Hintikka was not the first to make such observations. Cohen says: the sense of 'intuition' as an immediate non-inferential judgement, . . . began to prevail in the later 1940s. It then became fairly common, at least in North America, for intuitions to be explicitly invoked by philosophers . . . (Cohen, 1986, 77) ∗This paper is forthcoming in Metaphilosophy. This document is my own copy of the final version of this paper, not the official published version. Please do not rely on this version for citations, page references, &c. a number of minor changes will have been made in the published version. 1 (Indeed, intriguingly, the history of disquiet among philosophers over 'intuition', and the frequency with which philosophers use it, seems to go back even further. In 1946, a master's student at The University of Sheffield, Leslie Belton, wrote a dissertation on 'The Meaning and Use of the Term Intuition' (Belton, 1946). Belton says in the introduction: "No word in common use among philosophers is in more urgent need of an accepted definition than the term 'intuition', and no word bears such diversity of meaning" (Belton, 1946, 4). Nonetheless, although it may not involve consensus on precise dates, received wisdom has it that use of the word 'intuition' has exploded in analytic philosophy. If the received wisdom is correct, the following questions are prompted: Why has this terminological shift has taken place? Is it a purely terminological shift or is it perhaps symptomatic of a shift in philosophers' methods? Before addressing such questions, however, we need to know whether the received wisdom is correct. We need to know whether the supposed phenomenon to be explained exists. It does. As we shall see below, the proportion of philosophy articles indexed in JSTOR indulging in intuition-talk has grown from around 22% in the decade 1900-1909 to around 54% in the decade 2000-2009. And, so, we want to know why this has happened. If we want to know what best explains the explosion in 'intuition', then more empirical data will be helpful, i.e., beyond the simple finding that use of intuition-talk has grown in philosophy. Certain facts about the explosion may help us arbitrate between explanations. For instance, information about when the explosion took place and whether intuition-talk exploded elsewhere could be important. In the following, I present the results of an empirical study which shows that: (a) the explosion in the use of 'intuition' is far from confined to philosophy, in fact intuition-talk has been on the rise across a broad swathe of academia; and (b) nonetheless, intuition-talk has grown at a greater rate within analytic philosophy in particular. Before I report the empirical findings, however, I want to do two things by way of motivating a more careful empirical investigation into the explosion of intuition-talk. First, I want to quickly canvass the various types of explanation of the explosion which have been suggested in the philosophical literature. I note that the explosion which they seek to explain seems to be one which is confined to philosophy. Second, I report some suggestive evidence that casts some doubt on this picture: evidence that intuition-talk has exploded in a number of other areas, suggesting that our understanding of the explosion is impoverished. 2 Explaining the Explosion The picture that Goldman (2007) paints is that intuition-talk is on the rise but that no great methodological change drives this rise. He thinks that philosophers have always used intuitions (it isn't clear whether he thinks the rate of use has been constant). This suggests a picture on which the recent rise in intuition-talk is mainly a linguistic phenomenon. Cappelen offers a similar story, suggesting that one factor contributing to the explosion in intuition-talk is that philosophers have acquired, "a kind of intellectual/verbal virus (or tick) that started spreading about thirty to forty years ago" (Cappelen, 2012, 50), and that it is not motivated by any substantial shift in philosophical commitments or methodology. Cappelen notes that he has no satisfactory answer to how the 'virus' was caught, nor why it was so infectious. But, he thinks it has been influential, and particularly damaging in philosophical methodology. Cappelen thinks that intuitions play no important part in philosophy, but that "The virus helped convince those doing methodology that things called 2 'intuitions' play an important part in philosophical arguments" (Cappelen, 2012, 50). Others, on the other hand, think the change in philosophers' terminology is to be explained in terms of a change in their methodology, i.e., it is due to an increased use of intuitions themselves. The clearest example of such a view is that of Hintikka. He takes the explanandum to be as follows: Before the early 1960s, you could scarcely find any overt references [to intuition] . . . After the mid-1960s, you will find intuitions playing a major role in the philosophical argumentation of virtually every article or book. (Hintikka, 1999, 5) Hintikka thinks that philosophers started using intuitions in a big way in the wake of Chomsky's influential theories in linguistics. Chomsky's theories were so successful that they were taken to "provide a methodological paradigm of what can be done in those fields where the subject matter involves the tools of human thought and cognition" (Hintikka, 1999, 5), is the idea, and philosophers' increased use of intuitions is an attempt to replicate that success in philosophy. Although, Hintikka doesn't think that philosophers typically recognise this influence. The question as to what explains philosopher's increased use of intuition-talk is interesting by itself. However, it also seems that it has some potential methodological consequences. Certain types of explanation would generate novel worries about intuition-using methods. For instance, Hintikka claims that, "the linguistic parentage of contemporary philosophers' intuitionist methodology . . . constitutes a strong reason to be wary of it" (Hintikka, 1999, 5). Other explanations would draw attention to other problems. Cappelen thinks one of the main reasons that philosophers tend towards an intuitionist conception of their methods is the prevalence of intuition-talk in philosophy. However, he thinks that this is a big mistake, since the prevalence of intuition-talk in philosophy is largely the result of a 'verbal virus' rather than having anything to do with philosophers' methods. Let's quickly consider some other possible factors which we might think have contributed to the increased use of intuition-talk (some via increased appeal to intuitions themselves). Three are gestured at by Cappelen (2012): the emphasis on 'what we would say' from either ordinary language philosophy or late Wittgenstein; Moore's emphasis on the pretheoretic; and Rawls's use of 'intuition'. Three more deserve consideration. First, the socalled 'linguistic turn' may have played some role.1 Second, a particular approach in early 20th century philosophy of mathematics and the language used in describing it may have played a role. The approach in question is that of finding formal definitions with which to replace informal and vague intuitive notions.2 And, third, that the uses of 'intuition' in various parts of psychology, in the 1970s and 1980s, may have contributed to the explosion perhaps having come to philosophy through Stich (e.g., 1990) among others.3 As noted, all these suggestions seem to take the explanandum to be an explosion which was confined to philosophy.4 However, the supposed picture doesn't fit well with some suggestive evidence from elsewhere. 1Thanks to Jonathan Tallant for this suggestion. 2Thanks to Greg Currie for this suggestion. For an example of this sort of move, see discussion of Church's thesis. One description of Church's thesis that brings this theme out can be found in Shapiro (2006). 3The particular uses I have in mind are those of Kahneman, Tversky and colleagues (Kahneman et al., 1982; Kahneman and Tversky, 1973, 1982; Thagard and Nisbett, 1983; Tversky and Kahneman, 1981). This usage may have been influential especially in those parts of philosophy closest to cognitive science, including experimental philosophy. 4Of course, some of the factors appealed to would be capable of explaining changes outside of philoso3 3 Suggestive Evidence In light of the various explanations offered by philosophers, it is interesting to note that academics in some other fields have also explicitly noted an increased use of intuition-talk over recent decades.5 In relation to economics, Frantz notes:6 The increasing reliance on formal modeling and mathematics in economics after World War 2 kept intuition in the background of the profession. Yet, recently it has become almost commonplace for an economist to state during a presentation that, 'The intuition behind the model (and/or result) is' (Frantz, 2004, 135) Haidt and Kesebir (2007) look at the use of the word 'intuition' in psychology from 1985 to 2004. They find some evidence suggestive of growth. Notably, they present their findings as contrasting considerably with those of a similar previous study (Bastick, 1982) which showed extremely limited use of 'intuition' in psychology (in 1979). Haidt and Kesebir's main concern is intuition, rather than 'intuition', but their data speaks to both. Haidt and Kesebir's analysis categorises (non-incidental) uses of 'intuition' in research article titles into four groups. Two of these groups increased as a proportion of the total number of articles published between the decades 1985-1994 and 1995-2004. Uses in one category grew by 188%.7 Uses in a second category grew by 138%.8 The base rate-growth of the total number of articles-was 49%. Two other uses grew at and below the base rate respectively.9 Tallant (2013) conducts a survey of the use of 'intuition' in physics journals.10 His figures show that, between 2001 and 2011, the proportion of papers which use the words 'intuition', 'intuitive,' 'intuitively', 'counter-intuitive' and 'counter-intuitively' in five physics journals has steadily increased from 7.44% to 9.25%. Further searches on my part reveal that, in the same journals, the proportion rose steadily from 1.95% in the 1960s to 7.89% in the 2000s.11 And, finally, there is some evidence from outside the academy. First, a brief search of Google's NGram corpus (containing around 4% of all books ever published) reveals a phy. Chomsky should be expected to have influenced linguistics. The philosophy of mathematics may have influenced mathematics. Tversky, Kahneman and colleagues were working in psychology. However, changes in these other fields are clearly not considered part of the explanandum by those offering the respective explanations. 5When presenting these results in a number of places, various audience members have confirmed that they are aware of this trend in their fields. Among the more unexpected include an anecdotal observation that the use of the word 'intuition' has increased among horse trainers-the suspicion being that this is a result of an increased respectability of 'natural horsemanship' in the past 20 years. 6Thanks to Jonathan Tallant for pointing me at this source. This locution is one novel to me and, interestingly, implies that Frantz has observed some increase in methodological use of intuitions. I think more detailed qualitative work would be valuable in comparing the trends in usage across different disciplines. 7These were labelled 'personality facts' and concern a distinction between intuitive/experiential and analytical/rational thinking styles. Haidt and Kesebir attribute the growth of this category to the work of Epstein (citing Epstein, 1990). 8Haidt and Kesebir label this category 'anthropocentric facts'. It seems to concern intuitions about aesthetic matters. This growth use is claimed to be due to increased use in social psychology. 9These were 'plain facts', to do with things like maths problems, and 'behavioural', to do with decisionmaking and problem-solving. 10The five journals are the following: Physical Review Letters, Review of Modern Physics, Physical Review A-E, and Physical Review Special Topics Energy Beams. 11I used the same search engine as Tallant. This can be found at http://publish.aps.org/search (including only papers written in English). 4 Figure 1: Intuition-talk in Google's NGram Corpus notable increase (approx. fourfold) in use of such terms between 1800 and 2000 (see Figure 1, 5). The pattern also remains if we restrict ourselves to English fiction writing. I searched for 'intuition' and 'intuitive' in the period 1800 to 2000.12 In this period in fiction the frequency of 'intuition' and 'intuitive' each rose from around 1.5 to 5 tokens per million words.13 Second, a brief search of the TIME corpus which contains all copies of TIME magazine from 1923 2006 reveals a similar pattern.14 During the period 1923 1929, the frequency of 'intuition', etc., was 2.62 tokens per million words. During 2000-2006, the frequency was 8.4 per million. The general pattern between 1923 and 2006 is one of increase, although the pattern is not one of steady increase. The pattern suggested by these various observations isn't that the rise in intuition-talk in philosophy is an isolated phenomenon. Rather, the pattern suggested is that intuition-talk 12See Michel et al. (2011) for more on this resource. Simple search tool available at: http://books. google.com/ngrams. This particular search was conducted on 19/05/12. This search conducted 2/8/13 using python script available at http://www.culturomics.org/Resources/get-ngrams. 13These are rough figures based upon Google's NGram Viewer output graph. This particular search was conducted on 19/05/12. 14The corpus was created by Mark Davis at Brigham Young University. The search facility is available at http://corpus.byu.edu/time/. The search for this data was conducted on 28/10/13. The search terms were the following: 'intuition', 'intuitions', 'intuit', 'intuits', 'intuitive', and 'intuitively'. Thanks to Millar (2009) for drawing my attention to this resource. 5 is on the rise rather more generally-perhaps even across the board. And, if this is so, the canvassed suggestions (in section 2, 2) as to what explains the explosion in philosophy, seem likely to explain at most part of the phenomenon. In any case, the evidence just surveyed serves to demonstrate that our understanding of the nature of the explosion in intuition-talk in philosophy is impoverished. It seems that, if we want to understand why intuition-talk exploded in philosophy, we need to find out more about how the explosion in philosophy relates to any more general explosion. In the rest of the paper, I present evidence that strongly suggests that the growth of intuition-talk in philosophy is part of more general phenomenon. This suggests that the most important explanatory factors-which explain the explosion in philosophy-are likely to be factors which are not specific to philosophy. 4 Study A first step is to confirm whether intuition-talk has indeed exploded in philosophy and elsewhere; so we need data. There is an unfortunate lack of resources to turn to in order to gain such data. Corpora which allow for diachronic study of word frequencies in English, more generally, over the twentieth century are scarce and very small compared with corpora used for other purposes.15 This a problem for diachronic studies looking at English usage in general, let alone for studies which require looking particularly at academic writing and comparing different disciplines.16 Consequently, the method used in the present study has had to be a little less direct, and inventive. 4.1 Method I searched for the terms 'intuit', 'intuition', 'intuitive', 'intuitions', 'counter-intuitive', 'intuitively' and 'counter-intuitively' in all journal research articles published in English available through the JSTOR database.17 Using JSTOR, it is possible to ascertain both the number of articles published in each discipline in each decade and the number of articles mentioning one of the search terms, and thus calculate the proportion of articles published during each decade by disciple which mention the search terms. There are limitations to the data which are worth noting to avoid confusion. For instance, it doesn't give us manageable data concerning actual word frequencies and it doesn't allow us to easily distinguish between different ways of using the same words. Qualitative research looking at rather smaller samples of text would be necessary to conduct the latter. We should also bear in mind that JSTOR is not a perfect resource in that not every journal is indexed. Nonetheless, it does provide a fairly general coverage of academic publishing and a search facility which provides useful information-a feature not shared by any obvious alternatives. Other multidisciplinary indexing or search services which I considered 15See Millar (2009) for an extended discussion of the lack of appropriate resources. Millar recommends the use of the TIME corpus for diachronic studies. However, this is of no use for my purposes here. 16See Groom (2005) for a study which uses corpora that allow for the comparison of two disciplines-History & Literary Criticism-but not diachronic study. 17This can be found at http://dfr.jstor.org. JSTOR coverage for the decade 2000-2009 is not complete for all journals. However, since (i) we are working with proportions, and (ii) no large changes in trends are observed relating to this decade, I think that it is safe to use the data from this decade. The physical sciences are not well represented in JSTOR, so their absence here ought not to be taken to indicate a lack of growth in the use of 'intuition' in the physical sciences. 6 (e.g., Pubget, Google Scholar, and Springer) do not enable easy access to information that would allow one to track both the amount of articles indulging in intuition-talk and the total amount of articles published by discipline in a given time period. The headline finding is that I found that an increase in the proportion of articles using at least one of these terms was apparent across the broad swathe of academia indexed by JSTOR. Now for some more details. 4.2 Basic Results The figures showing the rise in proportions are shown in Table 2, 8. The figures for philosophy largely confirm the commonly assumed picture: that intuition-talk in philosophy has been on the rise in recent decades. The increase certainly seems to have been greatest from the 1950s onwards. Indeed, we might tentatively observe that prior to this there seems to have been a period of relatively little change in the proportion of philosophy articles engaging in intuition-talk. However, the explosion is far from confined to philosophy. Philosophy articles are generally more likely to indulge in intuition-talk-no other discipline really comes close until the 1980s-however, the general pattern of increased rates of indulgence in intuition-talk exists to some degree across most disciplines indexed. This can be clearly demonstrated as, even if we take data relating to philosophy articles out of the analysis, there is a significant effect of decade on the proportion of articles in a discipline mentioning the search terms per decade.18 Indeed every decade since the 1940s, saw a highly significant increase in the proportion of articles in a discipline mentioning the search terms compared with the previous decade.19 This suggests clearly that the explosion in use of 'intuition' and related words is not confined to philosophy. 4.3 Comparing Philosophy and Non-philosophy Having confirmed that there has been a very general increase in the rate of indulgence in intuition-talk, we can now ask whether the explosion in intuition-talk in philosophy has nonetheless been greater than in other disciplines. Table 1: Model 1 Model B Wald χ2 p Philosophy 2.233 9347.372 < 0.0005 Decade by Philosophy -.062 450.758 < 0.0005 Decade .165 12817.243 < 0.0005 Constant -2.324 40517.458 < 0.0005 We can use binary logistic regression analysis to see if we can predict whether an article mentions one of the search terms using the variables (i) decade , (ii) whether article 18Using a repeated measures ANOVA with a Greenhouse-Geisser corrections, F(1.53, 59.46) = 115.03, p < .0005). 19Details from post hoc tests using Bonferroni correction (asterisks indicate highly significant increase on previous decade): 1900s, m = 3.85, SD = .49; 1910s, m = 4.12, SD=.44 (p = 1); 1920s, m = 4.65, SD = .47 (p = 1); 1930s, m = 5.63, SD = .50 (p = .009)*; 1940s, m = 6.46, SD = .61 (p = .16); 1950s, m = 8.58, SD = .76 (p < .0005)*; 1960s, m = 10.68, SD = .78 (p < .0005)*; 1970s, m = 13.35, SD = .99 (p < .0005)*; 1980s, m = 15.40, SD = 1.13 (p < .0005)*; 1990s, m = 17.97, SD = 1.39 (p < .0005)*; 2000s, m = 20.55, SD = 1.67 (p < .0005)*. 7 Table Information: The first row gives the decade by decade proportions (in %) for all disciplines including those not exhibited. The rest of the disciplines are ranked in decreasing order by the proportion of articles mentioning the terms for the 2000s. Dashes indicate that no articles are indexed for a given discipline and decade. The searches for the data in this data were conducted on 4/9/12. Table 2: Indulgence in intuition-talk by decade and discipline Discipline 1900s 10s 20s 30s 40s 50s 60s 70s 80s 90s 2000s All disciplines 2.6 3.6 4.2 5.2 6.2 8.3 10.5 13.1 14.6 16.3 18.3 Philosophy 21.7 29.6 34.5 33.5 4.2 32.7 34.9 44.1 47.5 50.5 53.6 Finance 7.2 5 7 6 12.4 10.1 16 18.7 25.8 36.7 47 Marketing & Advertising - - 11.1 11.4 14.6 17.3 25.6 31.8 36.8 39.9 Business 7.1 6.4 6.2 6.5 10.1 13.4 16.3 20.1 25.7 32 39.3 Linguistics 3.9 5.1 4.3 5.1 5.9 5.7 15.2 22.8 24.6 32.4 39.2 Economics 6.7 6 6.1 7.1 9.9 13.2 14 16.5 21.6 27 34.5 British Stud. 8.1 6.4 8.9 12 13.3 22.9 19.5 24.8 27.8 30.1 33.5 Slavic Stud. - 18.8 17 19.2 20.7 19.4 24.5 23.7 27.6 33.2 Management & Org. Behavior - - - 8 18.1 21.1 19.8 23 29.2 32.9 Hist. of Science & Technology 8.8 10.9 15.9 13 12.7 17.2 21.7 30.4 31.1 33.4 32.5 Transportation Stud. - - - - - 13.4 18.4 21.7 26.6 32.2 Law 2 2.9 3.7 6.8 7.8 9.5 14.7 19.1 24.8 27.2 30.8 Religion 5 8.3 7.2 9.4 10.5 13.5 16.3 21.7 24 25.3 28.3 Sociology 8 6.9 7.3 8.8 9.5 11.7 14.7 20.2 21.5 25.2 27.9 Latin American Stud. 7.8 5 7.2 8.5 11 15 20.5 21.7 24.6 27.9 Political Sci. 5 5.8 7.8 12.6 13.2 16.2 17.4 18.7 20.8 22 27 Statistics 3.3 2.5 3.6 5.1 8.6 13.2 14.5 15.5 17.2 22 26.6 African Stud. 3.4 4.7 4.7 7.1 5.5 6.1 9.9 15.9 19 22.5 26.2 Public Policy & Admin. 2.9 2.7 4.3 6.4 10 13.7 19.3 22.1 24.2 25.9 History 3.8 4.8 5.9 7.5 9.3 12.3 16.1 20 21 24.2 25.7 Development Stud. - - - - - 12.4 8.6 18.4 21.7 25.3 Continued on next page 8 Table 2 – Continued from previous page Discipline 1900s 10s 20s 30s 40s 50s 60s 70s 80s 90s 2000s American Stud. 3.6 4.6 5.8 7.2 7.5 11.2 14.3 16.4 17.5 22 24.4 Anthropology 2.7 2.9 2.9 4.6 4.9 7.2 10.9 15.8 17.3 22.1 24 Music 4.9 6.5 7.8 6.2 6.1 7.5 7.5 10 13.2 18.2 23.8 Folklore 2.5 2.1 2.7 4.4 2.8 6 6.8 11.6 16.3 17.5 23.2 Jewish Stud. 6.7 7.1 5.5 9.1 13.3 12.4 12.7 16.3 20.8 24.3 22.8 Psychology 16.3 13.1 7.9 9.8 12.1 10.8 13.4 12.3 16.8 20.4 22.5 Film Stud. - - - 5 9.1 14.6 21.7 23.8 24.6 22.2 Asian Stud. 3.7 3.5 3.8 6.8 7.3 14.1 14.3 14.8 16.4 19.3 22 Middle East Stud. 2.1 3.7 4 5 5.4 7.7 11.4 15.2 14.9 18.2 21.6 Architecture & Architectural Hist. 0 0 8.7 8.3 6.1 10 10 10.1 15.3 18.4 20.4 Art & Art Hist. 2 3 5.8 3.8 7.3 10.2 10.8 12.1 13.9 16.6 19.5 American Indian Stud. 9.1 0 2.7 3.5 3.8 8.2 9.2 9.9 14.9 19.5 Performing Arts - - - 0 11.1 15.2 16.7 12.5 16.7 19.4 Language & Literature 5.5 5.5 4.6 6 7.6 8.9 12.2 14.2 15.4 16.2 18 Education 4.5 4.1 3.5 4 4.3 5.7 9.4 11.9 13.2 15.5 17.7 Feminist & Women's Stud. - - - - - - 6.6 8.8 12.6 17 Bibliography - 2.6 8.9 9 9.1 9.9 11.9 14 17.2 16.8 Geography 1.8 2.6 2.4 2.5 2.9 5.3 7.3 11 11 12.7 16.6 Classical Stud. 3.3 3.7 3.8 4.7 6.1 7.6 9.4 10.4 11.7 15.4 16.6 Population Stud. - - 0 7.2 9.3 8.1 9.2 11.8 14.1 16.3 Mathematics 2.2 3.5 5 6.5 7.4 8.7 8.6 9.3 10.8 12.7 15.5 African American Stud. 0 5.1 6.7 8.6 8.7 8.9 12.6 12.5 12.4 13.1 Archaeology 2.4 3 3.1 3.9 4.1 4.8 5.7 8 8.5 9.9 11.6 Ecology & Evolutionary Biology 1.1 1.5 1.4 2.1 1.9 3.2 5 8.1 8.5 9.7 11.2 Irish Stud. 2.1 3.9 4.2 6.2 5.9 8 8.5 9.7 10.9 9 10.8 Health Policy 0 0.5 0.3 0.7 0.9 2.7 6.2 8.6 10 8.6 9 Aquatic Sci. 1.9 2.8 2.8 2.9 4.2 5.6 7 8 8.4 8.6 Biological Sci. 1.2 1.8 2 2.6 2.7 4.4 6.7 7.9 7.8 7.6 8 Continued on next page 9 Table 2 – Continued from previous page Discipline 1900s 10s 20s 30s 40s 50s 60s 70s 80s 90s 2000s General Sci. 2.1 2.8 2.7 3.6 4.2 7 8.7 9 7.7 7 7.6 Library Sci. 5.4 5 5 3.6 2.5 4.3 5.8 6 6.9 7.3 7.4 Developmental & Cell Biology - - - - 2.5 9.3 16.9 19.5 14.2 6.7 Astronomy 1.2 0.8 0.6 1 0.7 0.6 1.4 3.9 5.6 7.6 6.4 Zoology 0.6 0.9 0.8 0.8 0.8 1.3 2.1 3.6 5.5 6.1 6.1 Paleontology 1.6 0.6 1 1.9 1.8 3.7 4 4.5 5.4 6.2 5.9 Health Sci. 1.6 1.9 1.6 1.4 1.6 1.8 1.9 2.8 4.1 5.1 5.9 Botany & Plant Sci. 0.5 0.7 1 1.4 1.7 3 6 6.5 5.5 5 5.2 10 was published in philosophy or elsewhere, and (iii) the interaction (of i and ii).20 If the interaction term were significant, this could be a good sign that the rate of growth was different from other disciplines. Table 1, 7, shows the various regression coefficients and Wald statistics. All are highly significant (at .01 levels). Although the interaction is significant, we should note that the regression coefficient is small and, anyway, negative. This means that the model predicts that the extent to which the proportion of philosophy papers engaging in intuition-talk exceeds the proportion of other papers that engage in such talk falls over time. To get a better idea as to the nature of this interaction we can consider some figures called odds ratios.21 We can ask what the model predicts about the odds that a philosophy paper engages in intuition-talk for each decade surveyed.22 We can also ask what the model predicts about the odds that any other paper does the same. And, we can then compare these odds by asking in what ratio they stand to each other-I call this the expected odds ratio. The expected odds ratios are displayed in Table 3, 11. The expected odds ratios steadily decrease over time, i.e., they show the extent to which (i) the odds that a philosophy paper engages in intuition-talk, exceed (ii) the odds that a non-philosophy paper will do the same, steadily decreasing over the surveyed period. Table 3: Expected Odds Ratios Decade Odds Ratio 95% Confidence Intervals Upper Lower 1900 9.33 9.45 9.21 1910 8.77 8.87 8.67 1920 8.24 8.33 8.15 1930 7.74 7.82 7.66 1940 7.28 7.35 7.21 1950 6.84 6.90 6.79 1960 6.43 6.48 6.38 1970 6.04 6.08 6.01 1980 5.68 5.71 5.65 1990 5.34 5.37 5.31 2000 5.02 5.05 4.99 We can also calculate what we might call the observed odds ratios directly from the data. This reveals a similar story (see Table 4, 12): there is a general downwards trend. However, the observed odds ratios do suggest that, if we want to properly understand the interaction, it may be worth treating the periods 1900-1950 and 1950-2009 separately. The reason for this is that, since the 1950s, the odds that a paper published in philosophy engages in intuition-talk have been (roughly) a steady five times the odds that a paper outside of philosophy would do the same. This suggests that we should perhaps be treating the two periods (before and after 1950) as exhibiting different trends. That the trends are 20Decade was coded 0-10. Place of publication was coded philosophy .5, non-philosophy -.5. A test of this model compared with a model containing only a constant (the intercept) was statistically significant, χ2(3, 5280019) = 178227.617, p < 0.0005. The model correctly classified 2.9% of those papers mentioning the search terms and 99.6% of those which did not. 21Because the interaction term is in the model we cannot read odds ratios straightforwardly from the regression coefficients. 22The model: Ŷ = -2.324 + 2.233 * Phil -.062 * Phil * Decade + .165 * Decade. 11 different for the first and second halves of the twentieth century is also suggested by the finding that it is only since the 1940s that non-philosophical disciplines have consistently seen a highly significant decade on decade rise in the proportion of articles mentioning the search terms (see Table 2, 8). Table 4: Observed Odds Ratios Decade Odds Ratio 95% Confidence Intervals Upper Lower 1900 11.39 12.83 10.11 1910 12.34 13.62 11.18 1920 13.10 14.38 11.94 1930 9.93 10.76 9.17 1940 8.45 9.10 7.85 1950 5.70 6.03 5.39 1960 4.75 4.99 4.53 1970 5.50 5.70 5.30 1980 5.56 5.74 5.38 1990 5.49 5.66 5.32 2000 5.43 5.58 5.28 Pursuing this thought, looking just at the period after 1950, binary logistic regression gives the model in Table 5 (p.12).23 In this model, the interaction is still less important: the interaction is only significant at the .05 level and not at the .01 level; the coefficient for the interaction is, although positive, rather smaller. This suggests the same picture: that the extent to which philosophy papers are more likely than other papers to engage in intuition-talk has not undergone great growth since the 1950s. Table 5: Model 2 Model Wald χ2 p Philosophy 1.606 1613.772 < 0.0005 Decade by Philosophy .010 4.595 .032 Decade .166 4798.034 < 0.0005 Constant -2.327 13551.247 < 0.0005 One way to illustrate this is to plot the data. In Figure 2, p.13, we can see the proportions of articles that engage in intuition-talk and the proportion of articles in all other disciplines from 1950s to 2000s. We can compare the line of fit for philosophy (the green line) with a regression line for the proportions in non-philosophical disciplines (the blue line).24 It is clear that the rates of increase are in the same ballpark (even though the actual proportions are generally much higher in philosophy). Interestingly, although it may look as if the rate of increase in philosophy is marginally greater, note that fixed increases, e.g., of 10%, on the y-axis do not represent the same absolute rate of growth because it represents percentage change in proportion. To illustrate, the increase from approximately 40% 23A test of this model compared with a model containing only a constant (the intercept) was statistically significant χ2 (3, 4291567) = 78033.860, p < 0.0005. The model correctly classified 3.1% of those papers mentioning the search terms and 99.5% of those which did not. 24Philosophy line: Ŷ = .443 * x – 831.14. Non-philosophy regression line: adj. r-squared .242, Ŷ = .24 * x – 459.18. 12 Figure 2: Proportion of Article mentioning 'Intuition' by Decade to 50% of philosophy between 1970s and 2000s for instance doesn't indicate as large a rate of increase as an increase over the same period from 10% to 20%- the former representing a 25% increase in proportion and the latter a 100% increase. Looking instead at the relative decade on decade increase in proportion gives a more accurate picture. In this second graph (Figure 3, 14), the green line is a line of fit for the proportion of philosophy articles mentioning the terms in each decade from the 1950s onwards.25 The blue line is a regression line for the proportion of non-philosophy articles mentioning the terms in each decade from the 1950s onwards.26 The emerging picture is that the rate of increase in intuition-talk in other disciplines has been rather higher than in philosophy, but that it has been decreasing over the period while the rate of increase in philosophy has remained relatively constant. 4.4 Comparing Analytic and Other Philosophy One remaining hypothesis is that the explosion in analytic philosophy has nonetheless been rather larger than non-philosophical disciplines. The figures for philosophy above, from JSTOR, lump analytic and continental philosophy together. One reason this failure to dif25Ŷ = .096 *x – 180.694 26Adj. r-squared .115, Ŷ = -.66*x + 1329.483. 13 Figure 3: Relative decade on decade increase in percentage 14 ferentiate is relevant is that within continental articles discussion of figures such as Kant, Bergson, Husserl, etc., seems likely to have been common right from the beginning. The word 'intuition' plays a large role in discussion of the work of these figures (in ways which are somewhat removed from those common in contemporary analytic philosophy). One way to try to probe this further is to compare the proportions of articles engaging in intuition-talk within publications that we can identify as 'staunchly analytic' to the proportions for articles published elsewhere. Table 6 (p.17) records the proportion of articles engaging in intuition-talk in Philosophical Review and Mind and compares them to the figures for the rest of philosophy.27 Philosophical Review and Mind are the first and fourth highest quality general philosophy journals as ranked in recent years by an important ranking among analytic philosophers.28 The second and third places are taken by Noûs and Journal of Philosophy. I don't include the data for Journal of Philosophy here, as a name change makes tracking the proportions difficult. I have left Noûs out, as it is a fairly recent journal, having published its first issue in 1967.29 There is a clear difference in the scale of the explosion between PR and Mind and the rest of philosophy. Figure 4 (p.16) shows clearly the trend that staunchly analytic publications have seen a greater rate of growth in the proportion of articles using 'intuition' and similar terms from the 1950s onwards. Table 7 (p.17) allows us to compare Mind and Philosophical Review to all other journals (in all disciplines). We can see that the difference is quite stark. The odds that a Mind or Philosophical Review paper published in the period 2000-2009 engages in intuition-talk are roughly 12 times the odds that a paper published elsewhere will do so! (And, again, we can see a pattern of increasing ratios since the middle of the twentieth century.) To sum up this section, it does seem that, even if philosophy generally has not seen a markedly larger explosion, Mind and Philosophical Review, and by inference analytic philosophy, have. In the 2000s, 86% of articles in Philosophical Review engaged in intuition-talk, this does suggest that some discipline specific explanations will have some role to play in explaining the explosion in intuition. It also seems that any analytic-philosophy-specific contribution to the recent explosion has played an important role only since 1950. 5 Conclusion The lessons that we should take from this study are fairly modest. Further empirical work will be required in order to make any concrete claims about what the causes of the explosion in intuition-talk have been, both in philosophy and elsewhere. Nonetheless, I think that there are three important lessons to be learned. The basic shape of the three lessons to be learned is as follows. We now have a better understanding of the phenomenon to be explained-the explanandum. What we have learned about the explanandum allows us to place restrictions on what a satisfactory explanation of the explosion would look like-upon 27The searches for the data in Table 6 were conducted on 4/9/12. 28The report for 2009 can be found at http://leiterreports.typepad.com/blog/2009/ 03/the-highest-quality-general-philosophy-journals-in-english.html. The report for 2012 can be found at http://leiterreports.typepad.com/blog/2012/04/ the-top-20-general-philosophy-journals.html. 29Nonetheless, in that short time the proportion of articles mentioning the relevant terms in Noûs has risen, demonstrating a spectacular increase, from 46.7% (1967-76) to 83.9% (2000s). 15 Figure 4: Proportion of philosophy articles mentioning search terms 16 Table 6: Proportions per decade in philosophy journals Journal(s) 1900s 10s 20s 30s 40s 50s 60s 70s 80s 90s 2000s Other 17.3 25.3 34.3 32.1 33.2 33.4 35.6 44.4 47.3 50 53.3 Mind 32.5 37.1 30.6 31.2 34.5 25.9 27.4 36.2 49.6 66.5 67.2 Phil. Review 29.5 43.7 40.6 44.7 42.7 31.2 33.5 53.6 63.3 73.3 86 Table 7: Odds Ratios: Mind & Phil. Review vs Everywhere Else Decade Odds Ratio 95% Confidence Intervals Upper Lower 1900s 17.73 21.34 14.73 1910s 18.42 21.74 15.61 1920s 12.56 14.84 10.63 1930s 11.48 13.42 9.82 1940s 9.91 11.69 8.40 1950s 4.33 5.08 3.69 1960s 3.55 4.11 3.06 1970s 4.54 5.22 3.95 1980s 6.65 7.81 5.67 1990s 11.11 13.51 9.14 2000s 11.95 14.96 9.55 17 the explanans. Let me say something about the lessons to be learned before moving on to note some limitations of the present study and some promising avenues for future research. Lesson number one is that the received wisdom is largely borne out by this study. Analytic philosophy does seem to have seen a large surge in intuition-talk since the 1950s and this surge has been greater than the increases observed both in philosophy more generally and in the rest of academia. All the same, we should note that it doesn't seem to be true that, for instance, 'in the early years of analytic philosophy, the terminology is not to be found'.30 Indeed in both Mind and Philosophical Review intuition-talk is common throughout the period surveyed. So, if we want to explain the explosion in usage within philosophy in recent decades, then explanations which aim to explain some phenomenon specific to analytic philosophy, e.g., many of the suggestions surveyed earlier, will doubtless have to play some minor role, but a minor role is the only role they will have to play. (It is, of course, possible that the explosion of intuition-talk in philosophy is a completely distinct phenomenon from that observed in other areas of academia, for all the evidence presented here. However, the best explanation of the evidence is not one which treats the appearance of a general pattern merely as a coincidence.) Lesson number two is that we can start to refine the pool of analytic-philosophy-specific factors which are plausible candidates for this minor role. Only factors whose contribution would be made in the latter half of the twentieth century seem to be plausible explanations for the greater rate of increase in intuition-talk in analytic philosophy. This is due to the fact that the greater of increase is really only clearly apparent from the 1970s onwards. Looking at the suggestions I canvassed earlier, it does seem that we can make some tentative refinements of this variety. Some of the suggested factors do still look plausible: any influence of Chomsky, Rawls, intuition-talk in 70s and 80s psychology, and (to a lesser extent) Wittgenstein and Ordinary Language Philosophy, plausibly might have been during this period. On the other hand, some of the other suggestions look less plausible; any influence of Moore or early 20th century philosophy of maths seems unlikely to account for the upturn in the rate of intuition-talk which begins in the latter 20th century. Lesson number three, perhaps the most important, is that we should not underestimate the extent to which the explosion in philosophy (even analytic philosophy) is part of a wider phenomenon. The findings of the study indicate that there has been a rather large growth in intuition-talk across a broad swathe of academia. It seems likely, therefore, that appeal to some more generally relevant factors will feature centrally in any complete explanation of why philosophers engage in quite so much intuition-talk as they do. Perhaps Cappelen is right to attribute much of the explosion in philosophy to some sort of verbal virus (the twist is that everyone had the virus). Of course, the question remains as to why intuition-talk has been increasing more generally. It seems unlikely that any more general trend is due to any great shifts in methodology. One reason I say this it that the methods employed across the different disciplines are very varied. Another is the suggestive data showing increases in usage outside of the academy, which suggest that the upturn may not be restricted to academia at all. However, beyond suggesting that the general terminology shift is likely not due to a general methodological shift, I have no particular explanation to advance. Although, this said, it is worth thinking about what explanations of such a phenomenon might be like. And so I offer a couple of suggestions, to which I have no particular commitment, simply in the spirit of illustrating the type of factors to which one might appeal 30Goldman's claim is that it is not to be found used to describe the practice of appealing to intuitions. My data don't show this to be false, a more detailed qualitative survey would be needed to confirm whether early uses describe intuition-use. 18 to explain a more general increase in intuition-talk. First, there might be connection with a number of studies indicate that levels of various relevant psychologically interesting characteristics have increased in recent generations, e.g., positive self-conceptions, extraversion and narcissism.31 There are a number of such studies, see, e.g., Twenge (2001); Twenge and Campbell (2010); Twenge and Foster (2008, 2010); Twenge et al. (2008a,b).32 This could be relevant since a society in which individuals come to have higher perceptions of their own worth, and who become more willing to share information about themselves, might well be expected to be one in which people became more likely to talk about their personal mental states and to report their instinctive reactions, i.e., one in which talking about their intuitions came to be more common. I think that it is likely factors such as these, e.g., facts about changing psychological dispositions or the social acceptability of certain types of discourse (perhaps within academic contexts), are the sorts of factors we should be thinking about. Second, one explanatory factor may be the increased fragmentation of the research community.33 The thought might be that academic writings are targeted at a much more homogeneous audience than they once were, because people address their work at a very narrow specific corner of academia. This being so, the expectation that one will be able to appeal to intuition about x and have your audience share your intuitive response to x, would be much higher. This could explain why academia as a whole saw a large increase in intuition-talk. Indeed, all sorts of things could be relevant. A third and final suggestion draws on the idea that the concept of intuition has been gendered historically, at least at times. It is possible that the increase in intuition-talk in the academy has something to do with the change in the proportion of female academics. The idea might be that this lead to a change in climate rather than that women use intuition-talk more often. As with the other suggestions, more data are needed to properly assess this suggestion's merits.34 As I say, these three suggestions are intended simply as an illustration of the type of factors that could generate such a shift.35 So the present study makes some important contributions to our understanding of the explosion in intuition-talk and helps us start to explain why the explosion occurred. And, this is not without consequence for philosophy and philosophical methodology. For one instance, it is not uncommon to premise the urgency of the methodological investigation of intuitions on linguistic facts (like Hintikka, 1999). The thought might be 'it seems almost every philosophy paper written in the past 10 years makes explicit appeal to intuition', and proceed to worry about the changing methods or assumptions undergirding this linguistic change. However, the findings of the present study show that generating methodological worries about intuitions in this way is problematic. Philosophers do use the word intuition 31Thanks to Ben McGorrigan for this suggestion. Levels of narcissism are measured using the Narcissistic Personality Inventory developed by Raskin and colleagues (Raskin and Hall, 1981, 1979; Raskin and Terry, 1988). 32Although, note that some meta-analyses question some of these findings (Donnellan et al., 2009; Trzesniewski et al., 2008). 33This was suggested by an audience member in Derby. 34The changing proportion of female authors in JSTOR has been examined, see West et al. (2012). However, the data are not rich enough to provide much insight for our purposes. 35Once we have a hypothesis about what might drive any more general increase-about the nature of the 'virus'-it would also be worth asking whether there is any reason to think philosophers would be particularly susceptible to picking up the language as compared with other disciplines (or perhaps other disciplines showing sharp rises over the same period, e.g., finance, marketing and business). 19 a lot nowadays, but the evidence suggest this is not due to any great shift in methods, so there is no particular reason to start worrying, e.g., What is this new method? Is it reliable? etc. (Of course, none of this is to say that we shouldn't be worried about philosophers' use of intuitions, just that, if we are going to be worried, we should be worried for better reasons.) The present study only goes so far. Further research-and particularly qualitative research-will be essential in order to get a clearer picture. Gathering and analysing such data will be a big project requiring time and resources. However, it will help us address a number of questions which the present study has a limited ability to address. I'll finish my noting a few of these questions. Answering these questions will not only help us pinpoint the explanation for the explosion, but will provide an invaluable source of insight into the methods of philosophers and other academics, including to what extent philosophers' methods are distinctive to philosophy. (1) How has the actual frequency of words such as 'intuition' and 'intuitively' changed in academia over the surveyed period? We can't make any direct inferences about word frequency from the present study since we have no information about article length or the number of 'intuition' tokens in each article. An increase in the proportion of articles using intuition-talk-such as I observe-could theoretically be explained by an increase in the length of academic articles (if, indeed, any such increase in length has occurred).36 While, it is possible to obtain data concerning word frequencies from the same JSTOR 'Data for Research' facility used for the present study, to organise this data into a form we could use to address this issue would have been too laborious for the present study (for a single researcher with limited time), as it is provided in files that containing the word frequency data for a single article each. However, it would be an interesting avenue for future research. (2) Has any particular type of use of intuition-talk seen a general increase across the academy? The present study is unable to distinguish different types of intuition-talk. It is important to ask to what extent the various disciplines are using intuition-talk in similar ways. Other disciplines sometimes use words like 'intuition' in some pretty unfamiliar ways-to philosophers, at least see, Abernathy and Hamm (1995); Frantz (2004); Haidt and Kesebir (2007); Tallant (2013)-and it is unclear from the present study whether the general explosion in intuition-talk has been an increase in only some of these uses. (3) We tentatively observed that the two halves of the twentieth century exhibited different trends-at least in philosophy. Is this perhaps due to different types of intuition-talk? This is a very interesting question. One naïve thought is that the initial decrease in the proportion of philosophy articles engaging in intuition-talk may be due to a decline in a particular way of using such language, perhaps due to a decline in Kant scholarship. Another similar thought, is that the same pattern is due to the rise of ordinary language philosophy via its pushing out of pure rationalist intuition-talk).37 Again further investigation is necessary, as without data it is unclear what this pattern is telling us. (4) How does the usage of intuition-talk in academia compare with intuition-talk outside the academy? This is an important question. Although there is evidence suggesting that growth in intuition-talk may be a quite general phenomenon, e.g., occurring in fiction 36Thanks to Tom Stafford for making this point clear. Although, note: it is implausible that the length of research articles has increased to an extent which would provide a complete explanation. In the 1900s, the proportion of articles using intuition-talk across all disciplines was 2.6% and in the 2000s, 18.3%. Article length would have to have increased by around 700% in order to account for this pattern. 37Thanks to Stephen Barker for this thought. 20 writing too, and further evidence suggests there may be important differences between academic usage and usage in ordinary English, e.g., Cappelen (2012) notes that uses of intuition-talk to modify contents was very rare outside philosophy. However, again, further research is needed to obtain a clear picture. I say this because Cappelen's data seem to include only one source from outside philosophy which is an academic text. This suggests to me that the difference he notes may be due simply to a difference between academic and non-academic English. And there is some evidence which supports my suspicion. I conducted a quick search of the corpus of British Academic Spoken English (BASE).38 This contains 35 token uses of intuition-talk, of which only two are clearly non-content related, suggesting that other academic disciplines use intuition-talk in similar ways to philosophers. Mailing Address Dr James Andow, Department of Philosophy, University Park, Nottingham, UK NG7 2RD. Acknowledgements Thanks to audiences in Birmingham, Leeds and Nottingham for comments on this material. Thanks to Greg Currie, Jules Holroyd, Jonathan Tallant, Jonathan Webber, Carl Baker, Ivar Hannikainen, Kelly Ann Schmidtke, Alexis Moschopoulos and Simon Read and to a number of anonymous referees for helpful comments. Acknowledgment is also due to the support of an AHRC-funded studentship. References Abernathy, C. and Hamm, R. (1995). Surgical intuition: What it is and how to get it, Hanley & Belfus Philadelphia, PA. Bastick, T. (1982). Intuition: How We Think and Act, John Wiley and Sons. Belton, L. J. (1946). 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