Multiple Independent & in

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Many scientists have told me how dis- “Sometimes the discoveries are simul- appointing it is to have their research taneous or almost so; sometimes a anticipated by other independent in- scientist will make a new discovery vestigators. To have your ideas pre- which, unknown to him, somebody else empted in print just as you are about to has made years before. ”d One of the publish is especially frustrating. A few most commonly cited examples is the in- studies suggest [hat anticipated research dependent formulation of the is an occupational hazard for the nraj”or- by Newton and Leibniz, which has been i[rv of active researchers. Indeed, some definitively described by A. Rupert investigators report being anticipated Halls Another is the theory of the several times in their careers. of the , independently Building on general trends of an- advanced by and Alfred ticipation within various fields he first Russel Wallace. observed in 1965,1 University of But multiple independent discovery is Wisconsin sociologist Warren Hagstrom not limited to only a few historical in- surveyed 1,718 US academic research stances involving [he giants of scientific scientists in 1974.2 Of these, 46.2qo research. On the contrary, Merton be- believed they were anticipated once or lieves that multiple discoveries, rather twice, and 16.4V0 more thought they than unique ones, represent the common were anticipated three or more times. In in science.~ 1971, Jerry Gaston, Southern Illinois Interest in the widespread phenome- University sociologist, surveyed 203 non of multiples in science has rekindled British high energy physicists. J He found a philosophical debate on the process of that 38V0 believed their results had been discovery and creativity in science. One anticipated once, and another 26%’omore side of the debate has its roots in the than once. These figures agree rather “great man” or “genius” theory of well with the simple theoretical models , proposed in the l%h century.7 of multiple discovery that will be dis- Traditionally opposed to this theory is cussed in this essay. the “social determinist” or ‘‘zeitgeis[” Anticipation or preemption of re- argument. ~ More recently, a “chance” search results is a subset of a wider phe- theory based on probabilistic models has nomenon referred to by historians and tried to account for the occurrence of sociologists as “multiple independent multiples.g discovery. ” Robert K. Merton, Colum- Jacob Schmookler, University of bia University sociologist of science, Minnesota economist, says the great defines what he calls “multiples” as in- man theory explained discovery and in- stances in which similar discoveries are vention primarily in terms of the in- made by scientists working indepen- dividuals who made them.T (p.189) dently of each other.d Merton says, Dean Simonton, social psychologist at

660 the University of at Davis, Ogburn and Thomas believed “that the adds that the individual scientists and became virtually inevitable inventors were believed to possess ex- as certain kinds of knowledge accumu- traordinary abilities, backgrounds, and lated in the cultural heritage and as personalities which allowed them, rather social developments directed the atten- than their “ordinary” colleagues, to tion of investigators to particular prob- make important discoveries. s Simonton Iems. ”b points out that thegenius or great man Simonton has labeled the social deter- theory ofcreativitycan’t adequately ex- minist argument the zeitgeist theory of plain the simultaneous appearance of creativity. 8 He says the social determin- independent discoveries. However, he ists claim that “the sociocultural system says it does explain one special case of as a whole, embodied as the spirit of the multiples—’’premature” discoveries times [zeitgeist], is ultimately respon- that were “rediscovered” by indepen- sible for any given technoscientific ad- dent investigators after a period of vance.”s While it is a plausible explana- years. I recently discussed the delayed tion of simultaneous independent dis- recognition of premature scientific dis- coveries, Simonton says that premature coveries ina separate essay.lo discoveries “must prove an embarrass- The social determinists acknowledge ment to zeitgeist theory.”s that mental ability plays an obvious role When Merton redirected the attention in discovery and , but they be- of sociologists and scientists to the im- Iieve that cultural factors are far more portance of multiple discoveries in important than individual personalities. 1952, J3 he recommended a moderate The distinguished anthropologist A. L. position between the opposing theories Kroeber was an early proponent of the of scientific creativity. Instead of per- social determinist argument. In a 1917 petuating “the false disjunction between article,ll he reasoned that there are the heroic theory centered on men of many people with high intelligence in a genius and the sociological theory large population at any given time. centered on the social determination of Thus, if a particular inventor had died as scientific discovery,”6 Merton proposed an infant, there is a good chance that the an alternative theory that combined invention would stiIl have been con- elements of both. He acknowledges the ceived by someone else. The that central position of the accumulated certain ideas or occur at the knowledge base in culture, but denies same time to different people proved, to that discovery and invention are in- Kroeber at least, that they’ ‘seem to have evitable as a resuk. b Merton points out been destined to come about precisely that the main ingredients of some dis- when they did” 1I because of cultural coveries were present in culture for factors. many years before they were finally A few years later in 1922, the sociolo- made. gists William Ogburn and Dorothy Also, he attributes a distinctive roIe to Thomas, Columbia University, com- genius but denies that the’ ‘great man’s” piled a list of 148 independent discoveries mentality gives him insights impercepti- and inventions made between 1420 and ble to the ordinary man.b Merton rede- 1WI. 12 They observed that the rate of fined genius in sociological rather than such repeated innovations increased psychological terms. The genius doesn’t with time. They concluded that cultural see something to which the ordinary evolution must account for the increased man is blind—rather, he sees more, and frequency of multiple independent in- more quickly. As a result, “The genius vention because inherited mental ability will have made many scientific discov- could not have significantly increased in eries altogether. . . . This means that 500 years. In fact, Merton observes, each scientist of genius will have con-

661 tributed the functional equivalent to the Table 1: Poisson distribution and simulta- advancement of science of what a con- neous discovery (see Price D J D. Z.i/de siderable number of other scientists will science, big science. New York: Columbia have contributed in the aggregate.’ ‘G University Press, 1963. p. 67). The great man theory predicts that the 1000 apples genius conceives of things far in advance Number of Merton-Barber simultaneous data cases and men of “the crowd” by virtue of his unique discoveries cases capability, and his ideas therefore stand o . [368]* alone. Merton’s expanded sociological 1 — 368 theory of genius predicts that the genius 2 179 184 will be involved in more multiple dis- 3 51 61 coveries than the ordinary scientist 4 17 15 because of a great number of discoveries 5 6 3 altogether. Merton cites many cases of 6 or more tl 1 the “multiplicity of multiples” among the great scientific thinkers. G interest- * i.e., there are 368 cases in which an apple is rrof picked. The remaining 632 apples are ingly, Simonton showed that more emi- picked, singly or multiply, by the thousand nent scientists are “still more likely to pickers for an akerage of 1,6—[hat is, 1.6 participate in multiples even after con- discoverers/discovery. trolling for individual differences in the number of notable contributions.”8 Several authors point out that Mer- are near the truth. For example, he says, ton’s modified social determinist posi- “One can calculate from Table 1 that tion, which denies both the inevitability about 37V0 of the apple pickers will of scientific discovery and a unique role make uncontested discoveries but the re- for individual genius, is actually com- maining 63V0 will be engaged in multip[e patible with a “chance” model of multi- discovery. It is worth noting that the ple discovery .7,~.ld Derek Price, Yale distribution of the discoveries is dif- University historian of science, sug- ferent from that of the discoverer. Some gested a “ripe apple” model using a 58V0 of the discoveries are unique and Poisson statistical distribution. He asks, the remaining 42V0 are shared in the “If there are 1000 apples in a tree, and multiple process. ” I5 1000 blindfolded men reach up at ran- Simonton also subjected the Merton- dom to pick an apple, what is the chance Barber list of 264 multiples to a of a man’s getting one to himself, or statistical analysis using a Poisson distri- finding himself grasping as well the hand bution.q Instead of arbitrarily defining of another picker, or even more than the number of “apples and pickers, ” one7~~14 The statistically expected Simonton set mean values ranging from distribution of multiples was then com- 0.8 to 1.6 to see which would most pared with an actual distribution among closely agree with the Merton-Barber 264 multiples compiled by Merton and distribution. He found that a mean Elinor Barber in 1961.6 As can be seen in value of 1.4 agreed most closely with the Table 1, the distributions agree to some Merton-Barber figures. With this mean, extent, especially between doublet, 41 Vo of the total discoveries would be triplet, and quadruplet discoveries. multiples, and 35V0 would be singletons. However, Price cautions that the results Simonton applied the same methods shouldn’t be given too much weight to the Ogburn-Thomas list of 148 muhi- since they are based on only approx- pies. The optimal mean in this case imate parameters. turned out to be 1.2. This value is close However, Price believes this ad- enough to the Merton-Barber mean of mittedly very simple and approximate 1.4 for Simonton to conclude that “the model makes interesting predictions that true [mean] is probably somewhat more

662 than unity and definitely less than two. century 72V0, 59V0 in the last half of the Hence, so far techno-scientific contribu- 19th century, and finally only 33V0 in tions hardly appear inevitable.”9 Simon- the first half of the 20th century.d ton also reconstructed the probable In light of his statistical analysis, frequencies of multiple discoveries from Simonton argues that the distribution of the Ogburn-Thomas list. He found that independent discoveries doesn’t support about 30070of the probable discoveries the idea that discoveries are inevitable, are “undiscoveries” —apples that were as the old social determinists argued. on the tree but were passed over by the Also, the genius theory is not supported pickers, to borrow Price’s imagery. This by the results. While Simonton doesn’t supports Merton’s statement that dis- deny that social factors can influence the coveries are not necessarily inevitable. d content and intensity of scientific cre- When Simonton compared the prob- ativity, he concludes that “chance seems able frequency of multiple discovery to to have usurped the dominating position the actual number of cases reported by in explicating the appearance of multi- Ogburn and Thomas, he found that low ples in the and tech- grade multiples are less likely to be nology. ”g This conclusion is compatible reported than high grade multiples. Low with Price’s ripe apple model and grade multiples involve only two or three Schmookler’s simple probabilistic argu- independent researchers while high ment.7 grade multiples involve more than three. In a later study, Simonton examined Simonton says that the number of multi- the zeiigeist, genius, and chance theories ples involving six independent discover- of multiple discovery in relation to four ers probably amounts to ten times the separate “critical tests” to determine number of reported cases, while those which is most plausible. g The four tests involving two discoverers were underre- were conducted on two samples of mul- ported by a factor of 44! tiples, one listing 199 multiples and the This supports Merton’s claim that the other 579. Simonton found thal “the number of reported multiples is much position that best meets all critical tests lower than the number of actual multi- is the chance theory. . . .Despite the ~- ples. He gives several reasons why parent explanatory superiority of t_he multiples are underreported.d For exam- chance theory, however, the other two ple, the announcement of a discovery or theories are not completely overturned.”s invention forestalls simultaneous re- In effect, all three theories contribute to search efforts that could have produced an explanation of multiple discoveries similar results. Researchers may aban- and scientific creativity. don their projects and not report their Merton’s expanded sociological mod- independent but identical results once el approaches a “unified theory” of they’ve been anticipated in print. Also, multiple discovery by combining ele- many singletons prove in later years to ments of both the zeitgeist and genius be rediscoveries of prior research that perspectives, and it is compatible with either wasn’t published or wasn’t recog- the chance model. [f we affirm only the nized at the time. chance model, we have to consider mul- Lastly, fewer scientists now engage in tiples as mere coincidences whose occur- priority disputes when multiple discover- rence is uniform across all scientific dis- ies are made: uncontested multiples are ciplines. But Merton believes these “co- simply less often noticed. Merton cites incidental” multiples are not trivial the following figures to demonstrate this scientific phenomena—rather, they are point: before 1700, 92r170of the multiple significant research areas for sociologists discoveries were contested, in the 18th and historians of science.

663 As Merton correctly points out, “The opiate receptor research, co-citation sheer fact that multiple discoveries are analysis revealed the multiple discovery made by scientists working indepen- of opiate receptors in rat brain.~b dently of one another testifies to the . . Another study based on 1S1’s data base fact that, though remote in space, they using the co-citation model identified are responding to much the same social the simultaneous discovery of a precur- and intellectual forces that impinge sor molecule for collagen called “procol- upon them all. ”~ [t would be worthwhile lagen. ”17 Still another co-citation study to uncover those common social and in- of ISI’s data uncovered the joint tellectual forces, particularly at a time discovery of reverse transcription, I~ I‘ve when so much stress is put on the spe- discussed the details of 1S1’s co-citation cialization of research fields. By study- analysis procedures in a separate essay, ing the occurrence and frequency of which also explained the difference be- multiple discoveries, perhaps we’ll be tween co-citation and bibliographic able to keep sight of the forest of science coupling. 19 through the increasingly narrow spe- In the area of technology, the US Pat- cialt y trees. ent Office (and other patent offices One of the earliest projects we under- around the world) is a potentially vast took by use of the Science Citation reservoir of information on duplicate Index? (SCImj was the detection of un- and multiple discovery. One would ex- witting duplications of research. I have pect that patents show the same sort of reported many times on the examples we Poisson distribution of multiple dis- discovered that might have been uncov- coveries as we have discussed for ered through bibliographic coupling, science. Ogburn and Thomas observed that is, finding papers which cited one or in 1922 that almost half of the patent ap- more papers in common. It would be a plications in the US were denied. 12 massive computer effort but it is an ex- Many of these may have been denied periment we ought to try one day. If two because they duplicated already granted independent authors cite four or more patents. However, Schmookler points authors in common it is not unusual, but out that patents may be denied because such coupling may indicate they are only one of myriad “claims” are already working on the same idea. If editors had protected, and identical claims are prac- immediate access to such files how many tically non-existent.7 (p. 191-2) inadvertent published duplications But this question is difficult to decide might be avoided? Perhaps the increased because some claims are denied on use of word processors and microcom- grounds that aren’t revealed once the puters to prepare manuscripts will mean patent is approved and printed. How- that authors’ bibliographies can be ever, one can examine the “file wrap- matched against our master files, not pers” in the US Patent Office library in only to insure bibliographic accuracy, Washington. 1often did this when 1 first but also to identify degrees of biblio- experimented with Patent Citation In- graphic coupling or even earlier pre- dexes,zo based on the idea of attorney mature discoveries. Arthur Seidel.21 I’ll have more to say ISIS’s co-citation analysis of scien- about this when the subject of patents is tific literature is another way multiple reviewed in a future essay. independent discoveries may be iden- **** tified. Co-citation is the number of times two earlier published papers are My thanks to A&red Welljanrs-Dorof cited together in the more recent lit- for his help in the preparation of this erature. As 1 pointed out in my essay on essay. 01’36) m

664 REFERENCES

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