We listed. You tweeted (often in outrage). We listened (mostly). And now we’re doubling down on our recent list of Twitter’s 50 most popular researchers with a revision that names 100 of the most followed scientists on the social media platform. (See below for that list, or download our updated spreadsheet, which marks the additions in red.)
The first list—in case you missed it last month—was part of a story examining the use of Twitter by scientists, prompted by the furor that had erupted over the so-called Kardashian Index (K-index). This metric, whose inventor says he meant it in fun, compared a researcher’s number of Twitter followers with the number of citations to his or her academic papers. Our story explored why some highly respected scientists had embraced tweeting, but we also made a stab at compiling a list of the most followed researchers on Twitter, which online we dared to headline “The top 50 science stars of Twitter.”
Well, make a list of the “best,” “worst,” or “top” and you’re asking for trouble. Many, including biologist Jonathan Eisen, who was one of our original top 50 and who has argued that tweeting helps his career, took to Twitter to question why we conferred stardom based on a simple ranking of follower number, with some calling that a meaningless popularity contest. Others suggested alternative ways to measure the impact a scientist has on Twitter, among them retweets, direct mentions, and Klout Score. Euan Adie of Altmetric probably took the most serious look at an influence-based ranking of science-themed Twitter accounts with this blog post on the “The Real Science Stars of Twitter.”
And then there were the many Twitter stars we failed to spot. We had clear criteria and an explicit methodology (repeated below the revised list), but the original list had numerous and notable omissions—sorry, Francis Collins (@NIHDirector) and Sylvia Earle (@SylviaEarle), for example! And kudos to Noah Gray (@NoahWG) who noticed that rock star (and Ph.D. astrophysicist) Brian May fit our criteria—he’s now #12 on our new list.
Some decried the lack of scientists of color or female scientists on our list—just four women made the top 50, for example—and noted that our search strategy, which started with a handful of Twitter celebrity scientists and looked at who they followed, likely biased our discoveries toward white males. In our story, we took the identified gender disparity at face value and explored some reasons why women might avoid Twitter or be less followed. But a slew of women scientists are clearly popular on Twitter—the hashtag #womentweetsciencetoo quickly collected an impressive list, most if not all noted in this blog post, and we’ve added those with the most followers. We also reviewed several other public Twitter lists, including the lengthy BLACKandSTEM created by Stephani Page (@ThePurplePage), for other omissions.
In the end, we added anyone suggested to Science who met our criteria and who had more than 11,600 followers, enough to qualify for 50th position in the original list. We also opened the list to economists, as their field has its own Nobel Prize and is represented by one of the sections of AAAS (the publisher of Science). The result: Our list more than doubled in size and now includes a large number of newly added women. But few women cracked the revised list’s top 50—just seven—which now has a threshold of more than 33,000 followers, versus 11,600 in the original list. The newly added economists, 18 in total, are partly to blame; they are highly followed on Twitter and are predominantly male. (We list the top 100 below, but our spreadsheet includes additional suggestions that pushed the total beyond that.)
A note to doctors: Our original list included several highly cited physician researchers who we didn’t notice bypassed our Ph.D. requirement. We’ve kept the originals on the new list but declined suggestions that we add other M.D.-only physicians—perhaps they can petition a medical journal to create their own list of Twitter stars? Other than that, we’ve made our best effort to include everyone who qualifies.
And with that, here’s 100 of the most followed scientists on Twitter …
1. Neil deGrasse Tyson, Astrophysicist
2,460,000 followers @neiltyson
Citations: 159 K-index: 11,220
Total number of tweets: 4,001
Hayden Planetarium, United States2. Brian Cox, Physicist
1,450,000 followers @ProfBrianCox
Citations: 33,531 K-index: 1,193
Total number of tweets: 10,400
University of Manchester, United Kingdom3. Mike Massimino, Mechanical engineer/astronaut
1,290,000 followers @Astro_Mike
Citations: 5,459 K-index: 1,898
Total number of tweets: 1,556
NASA, United States4. Paul Krugman+, Economist
1,250,000 followers @NYTimesKrugman
Citations: 139,845 K-index: 651
Total number of tweets: 5,754
Princeton University, United States5. Richard Dawkins, Biologist
1,030,000 followers @RichardDawkins
Citations: 49,631 K-index: 748
Total number of tweets: 19,300
University of Oxford, United Kingdom6. Ben Goldacre, Physician
345,000 followers @bengoldacre
Citations: 1,086 K-index: 851
Total number of tweets: 47,400
London School of Hygiene & Tropical Medicine, United Kingdom7. Andr̩ Kuipers, Physician/astronaut
332,000 followers @astro_andre
Citations: 6,344 K-index: 465
Total number of tweets: 1,749
European Space Agency8. Phil Plait, Astronomer
325,000 followers @BadAstronomer
Citations: 254 K-index: 1,276
Total number of tweets: 47,300
Bad Astronomy, United States9. Michio Kaku, Theoretical physicist
315,000 followers @michiokaku
Citations: 5,281 K-index: 468
Total number of tweets: 1,139
The City College of New York, United States10. Nouriel Roubini, Economist
313,000 followers @nouriel
Citations: 17,484 K-index: 317
Total number of tweets: 10,200
New York University, United States11. Sam Harris, Neuroscientist
231,000 followers @SamHarrisOrg
Citations: 2,416 K-index: 441
Total number of tweets: 2,725
Project Reason, United States12. Brian May, Astrophysicist/guitarist
206,000 followers @DrBrianMay
Citations: 34 K-index: 1,539
Total number of tweets: 8,002
Imperial College London, United Kingdom (& Queen)13. Hans Rosling, Global health scientist
185,000 followers @HansRosling
Citations: 1,703 K-index: 395
Total number of tweets: 2,733
Karolinska Institute, Sweden14. Tim Berners-Lee, Computer scientist
183,000 followers @timberners_lee
Citations: 51,204 K-index: 132
Total number of tweets: 556
Massachusetts Institute of Technology, United States15. Richard Florida, Economist
177,000 followers @Richard_Florida
Citations: 36,537 K-index: 142
Total number of tweets: 45,800
University of Toronto, Canada16. Nobuo Ikeda, Economist
170,000 followers @ikedanob
Citations: 2,026 K-index: 343
Total number of tweets: 47,500
Agora Institute, Japan17. Jeffrey D. Sachs, Economist
164,000 followers @JeffDSachs
Citations: 112 K-index: 837
Total number of tweets: 5,865
Columbia University, United States18. P. Z. Myers, Biologist
156,000 followers @pzmyers
Citations: 1,364 K-index: 358
Total number of tweets: 25,700
University of Minnesota, Morris, United States19. Alexander Gerst, Astronaut
154,000 followers @Astro_Alex
Citations: 163 K-index: 697
Total number of tweets: 2,250
European Space Agency20. Steven Pinker, Cognitive scientist
145,000 followers @sapinker
Citations: 49,933 K-index: 105
Total number of tweets: 1,674
Harvard University, United States21. Richard Wiseman, Psychologist
135,000 followers @RichardWiseman
Citations: 4,687 K-index: 209
Total number of tweets: 22,600
University of Hertfordshire, United Kingdom22. Ryugo Hayano, Nuclear physicist
124,000 followers @hayano
Citations: 956 K-index: 319
Total number of tweets: 56,500
University of Tokyo, Japan23. Toshiyuki Masui, Computer scientist
122,000 followers @masui
Citations: 3,338 K-index: 210
Total number of tweets: 29,900
Keio University, Japan24. Marion Nestle, Nutritionist
118,000 followers @marionnestle
Citations: 7,176 K-index: 159
Total number of tweets: 3,944
New York University, United States25. Dambisa Moyo, Economist
104,000 followers @dambisamoyo
Citations: 1,612 K-index: 226
Total number of tweets: 2,084
Barclays, United Kingdom26. Lawrence M. Krauss, Theoretical physicist
104,000 followers @LKrauss1
Citations: 10,206 K-index: 125
Total number of tweets: 1,632
Arizona State University, United States27. Danah Boyd, Social media scientist
103,000 followers @zephoria
Citations: 16,274 K-index: 107
Total number of tweets: 4,755
Microsoft Research, United States28. Karen Nyberg, Astronaut
103,000 followers @AstroKarenN
Citations: 87 K-index: 570
Total number of tweets: 856
NASA, United States29. Atul Gawande, Surgeon/public health scientist
98,100 followers @Atul_Gawande
Citations: 14,106 K-index: 107
Total number of tweets: 2,139
Harvard University, United States30. Nassim Taleb, Statistician
79,100 followers @nntaleb
Citations: 6,523 K-index: 110
Total number of tweets: 427
New York University, United States31. Oliver Sacks, Neurologist
77,800 followers @OliverSacks
Citations: 13,883 K-index: 85
Total number of tweets: 754
New York University, United States32. Dan Ariely*, Psychologist/behavioral economist
74,300 followers @danariely
Citations: 16,766 K-index: 76
Total number of tweets: 1,098
Duke University, United States33. Alice Roberts, Clinical anatomist
68,900 followers @DrAliceRoberts
Citations: 1,850 K-index: 143
Total number of tweets: 8,333
University of Birmingham, United Kingdom34. Freek Vonk, Biologist
68,400 followers @freekvonk
Citations: 653 K-index: 199
Total number of tweets: 6,523
Naturalis Biodiversity Center, the Netherlands35. William Easterly*, Economist
63,200 followers @bill_easterly
Citations: 41,935 K-index: 48
Total number of tweets: 9,817
New York University, United States36. Justin Wolfers, Economist
62,600 followers @JustinWolfers
Citations: 9,314 K-index: 78
Total number of tweets: 16,600
University of Michigan, United States37. Jim Al-Khalili, Theoretical physicist
60,900 followers @jimalkhalili
Citations: 2,052 K-index: 123
Total number of tweets: 9,165
University of Surrey, United Kingdom38. Tim Noakes, Sports scientist
48,200 followers @ProfTimNoakes
Citations: 1,306 K-index: 112
Total number of tweets: 13,100
University of Cape Town, South Africa39. Austan Goolsbee, Economist
47,700 followers @Austan_Goolsbee
Citations: 4,924 K-index: 73
Total number of tweets: 2,624
University of Chicago, United States40. Eric Topol*, Geneticist
46,100 followers @EricTopol
Citations: 152,453 K-index: 23
Total number of tweets: 5,035
The Scripps Research Institute, United States41. Kaushik Basu, Economist
45,800 followers @kaushikcbasu
Citations: 11,476 K-index: 53
Total number of tweets: 2,089
World Bank42. Tyler Cowen, Economist
45,600 followers @tylercowen
Citations: 4,388 K-index: 72
Total number of tweets: 11,200
George Mason University, United States43. Dani Rodrik, Economist
45,500 followers @rodrikdani
Citations: 67,680 K-index: 30
Total number of tweets: 10,500
Institute for Advanced Study, United States44. Brian Greene, Theoretical physicist
39,900 followers @bgreene
Citations: 11,133 K-index: 47
Total number of tweets: 197
Columbia University, United States45. Melanie Greenberg, Clinical psychologist
37,600 followers @DrMelanieG
Citations: 1,924 K-index: 77
Total number of tweets: 82,300
Private practice, United States46. Joseph E. Stiglitz+, Economist
35,200 followers @JosephEStiglitz
Citations: 169,474 K-index: 17
Total number of tweets: 166
Columbia University, United States47. Sylvia Earle, Marine biologist/oceanographer
35,100 followers @SylviaEarle
Citations: 890 K-index: 92
Total number of tweets: 1,625
National Geographic, United States48. Marcus du Sautoy, Mathematician
34,800 followers @MarcusduSautoy
Citations: 1,472 K-index: 78
Total number of tweets: 3,572
University of Oxford, United Kingdom49. Francis Collins*, Physician-geneticist
34,200 followers @NIHDirector
Citations: 124,119 K-index: 19
Total number of tweets: 531
National Institutes of Health, United States50. Sean Carroll, Theoretical physicist
33,800 followers @seanmcarroll
Citations: 14,373 K-index: 36
Total number of tweets: 7,352
California Institute of Technology, United States51. Robert Winston, Fertility scientist
32,200 followers @ProfRWinston
Citations: 7,359 K-index: 43
Total number of tweets: 446
Imperial College London, United Kingdom52. Jared Bernstein, Economist
31,200 followers @econjared
Citations: 5,310 K-index: 46
Total number of tweets: 3,288
Center on Budget and Policy Priorities, United States53. Bruce Betts, Planetary scientist
29,000 followers @RandomSpaceFact
Citations: 91 K-index: 158
Total number of tweets: 1,666
The Planetary Society, United States54. Carolyn Porco, Planetary scientist
26,700 followers @carolynporco
Citations: 2,741 K-index: 49
Total number of tweets: 12,900
Space Science Institute, United States55. Adam Grant, Organizational psychologist
26,500 followers @AdamMGrant
Citations: 4,317 K-index: 42
Total number of tweets: 1,452
The Wharton School, University of Pennsylvania, United States56. Sebastian Thrun+, Computer scientist
25,800 followers @SebastianThrun
Citations: 54,907 K-index: 18
Total number of tweets: 187
Stanford University, United States57. Jonathan Eisen*, Biologist
25,600 followers @phylogenomics
Citations: 41,804 K-index: 20
Total number of tweets: 47,237
University of California, Davis, United States58. David "Danny" Blanchflower, Economist
24,600 followers @D_Blanchflower
Citations: 16,960 K-index: 25
Total number of tweets: 42,094
Dartmouth College, United States59. J. Craig Venter, Genomicist
24,200 followers @JCVenter
Citations: 75,931 K-index: 15
Total number of tweets: 373
J. Craig Venter Institute, United States60. Vaughan Bell, Neuroscientist
24,200 followers @vaughanbell
Citations: 836 K-index: 65
Total number of tweets: 10,997
King's College London, United Kingdom61. Robert Simpson, Astronomer
22,300 followers @orbitingfrog
Citations: 7,968 K-index: 29
Total number of tweets: 11,600
University of Oxford, United Kingdom62. Michael E. Mann*, Meteorologist
21,700 followers @MichaelEMann
Citations: 15,214 K-index: 23
Total number of tweets: 20,500
Pennsylvania State University, United States63. Dean Baker, Economist
21,300 followers @DeanBaker13
Citations: 10,758 K-index: 25
Total number of tweets: 7,285
Center for Economic and Policy Research, United States64. Amy Cuddy, Social psychologist
21,300 followers @amyjccuddy
Citations: 6,175 K-index: 30
Total number of tweets: 4,017
Harvard University, United States65. Mark Thoma, Economist
20,800 followers @MarkThoma
Citations: 799 K-index: 57
Total number of tweets: 42,100
University of Oregon, United States66. David Eagleman, Neuroscientist
20,100 followers @davideagleman
Citations: 2,768 K-index: 37
Total number of tweets: 1,482
Baylor College of Medicine, United States67. Jerry Coyne, Biologist
20,100 followers @Evolutionistrue
Citations: 16,817 K-index: 21
Total number of tweets: 7,380
University of Chicago, United States68. Noah Smith, Economist
19,900 followers @Noahpinion
Citations: 5,483 K-index: 29
Total number of tweets: 34,800
Stony Brook University, United States69. Gary King*, Political scientist
19,800 followers @kinggary
Citations: 36,858 K-index: 16
Total number of tweets: 3,104
Harvard University, United States70. Sinan Aral, Information sciences
19,100 followers @sinanaral
Citations: 3,306 K-index: 33
Total number of tweets: 5,696
Massachusetts Institute of Technology, United States71. Mike Brown, Astronomer
18,700 followers @plutokiller
Citations: 7,870 K-index: 24
Total number of tweets: 9,888
California Institute of Technology, United States72. Pamela L. Gay, Astronomer
18,400 followers @starstryder
Citations: 248 K-index: 73
Total number of tweets: 12,900
Southern Illinois University, Edwardsville, United States73. Jean Francois Gari̩py, Neuroscientist
18,100 followers @JFGariepy
Citations: 187 K-index: 78
Total number of tweets: 3,247
Duke University, United States74. Robert Metcalfe, Computer scientist
16,600 followers @BobMetcalfe
Citations: 5,251 K-index: 25
Total number of tweets: 16,300
University of Texas, Austin, United States75. Daniel Gilbert+, Psychologist
16,200 followers @DanTGilbert
Citations: 28,576 K-index: 14
Total number of tweets: 1,301
Harvard University, United States76. Daniel Levitin, Neuroscientist
15,800 followers @danlevitin
Citations: 5,852 K-index: 23
Total number of tweets: 3,040
McGill University, Canada77. Paul Bloom, Psychologist
15,700 followers @paulbloomatyale
Citations: 14,369 K-index: 17
Total number of tweets: 2,009
Yale University, United States78. Andrew Maynard, Environmental health scientist
15,600 followers @2020science
Citations: 10,543 K-index: 19
Total number of tweets: 16,300
University of Michigan Risk Science Center, United States79. David Grinspoon, Astrobiologist
15,600 followers @DrFunkySpoon
Citations: 2,914 K-index: 28
Total number of tweets: 9,736
Library of Congress, United States80. Pascal Wallisch, Neuroscientist
15,400 followers @Pascallisch
Citations: 85 K-index: 86
Total number of tweets: 1,118
New York University, United States81. Dorothy Bishop, Neuropsychologist
15,400 followers @deevybee
Citations: 28,848 K-index: 13
Total number of tweets: 14,800
University of Oxford, United Kingdom82. John Lennox, Mathematician
15,400 followers @ProfJohnLennox
Citations: 2,443 K-index: 29
Total number of tweets: 71
University of Oxford, United Kingdom83. Sarah-Jayne Blakemore, Cognitive Neuroscientist
15,200 followers @sjblakemore
Citations: 12,819 K-index: 17
Total number of tweets: 5,661
University College London, United Kingdom84. Matt Lieberman, Neuroscientist
15,000 followers @social_brains
Citations: 13,099 K-index: 17
Total number of tweets: 3,128
University of California, Los Angeles, United States85. Seth Shostak, Astronomer
14,800 followers @SethShostak
Citations: 427 K-index: 49
Total number of tweets: 299
SETI Institute, United States86. Amy Mainzer, Astronomer
14,700 followers @AmyMainzer
Citations: 1,516 K-index: 33
Total number of tweets: 2,295
Jet Propulsion Laboratory, United States87. Katie Mack, Astrophysicist
14,600 followers @AstroKatie
Citations: 364 K-index: 51
Total number of tweets: 44,300
University of Melbourne, Australia88. Daniel MacArthur, Genomicist
14,500 followers @dgmacarthur
Citations: 7,208 K-index: 20
Total number of tweets: 15,800
Harvard Medical School, United States89. John Allen Paulos, Mathematician
14,400 followers @JohnAllenPaulos
Citations: 1,494 K-index: 32
Total number of tweets: 4,167
Temple University, United States90. Ves Dimov, Immunologist
14,300 followers @DrVes
Citations: 224 K-index: 58
Total number of tweets: 32,300
University of Chicago, United States91. Simon Baron-Cohen, Psychopathologist
14,100 followers @sbaroncohen
Citations: 85,757 K-index: 9
Total number of tweets: 121
University of Cambridge, United Kingdom92. Catherine Qualtrough, Astrophysicist
13,700 followers @CatherineQ
Citations: 187 K-index: 59
Total number of tweets: 107,000
University of North Carolina, Charlotte, United States93. Deborah Berebichez, Physicist
13,100 followers @debbiebere
Citations: 12 K-index: 137
Total number of tweets: 7,039
ThoughtWorks, United States94. Uta Frith, Cognitive scientist
13,000 followers @utafrith
Citations: 49,700 K-index: 9
Total number of tweets: 3,645
University College London, United Kingdom95. Karen James, Biologist
12,900 followers @kejames
Citations: 1,032 K-index: 32
Total number of tweets: 62,600
Mount Desert Island Biological Laboratory, United States96. Brian Krueger, Genomicist
12,800 followers @LabSpaces
Citations: 156 K-index: 59
Total number of tweets: 35,800
Duke University, United States97. Helen Czerski, Physicist/oceanographer
12,300 followers @helenczerski
Citations: 61 K-index: 76
Total number of tweets: 2,211
University College London, United Kingdom98. Michael Eisen, Biologist
12,300 followers @mbeisen
Citations: 69,270 K-index: 8
Total number of tweets: 16,400
University of California, Berkeley, United States99. Trisha Greenhalgh*, Public health scientist
12,200 followers @trishgreenhalgh
Citations: 23,930 K-index: 11
Total number of tweets: 11,700
Queen Mary University of London, United Kingdom100. Robert Geller, Seismologist
12,100 followers @Rjgeller
Citations: 6,261 K-index: 17
Total number of tweets: 3,772
University of Tokyo, Japan
Some on our list also appear on the 2014 Thomson Reuters Highly Cited Researchers list (*) or the Scholarometer’s top 100 authors (+) ranking, and each is noted with a symbol; Micah Allen had slightly fewer followers than Robert Geller on the day we verified numbers, making Geller #100
Survey methods (adapted from original story):
The list of most followed scientists compiled here is far from scientific. To identify Twitter science stars, we began with celebrity scientists such as Neil deGrasse Tyson and checked out which scientists they followed. We also referenced online lists of scientists to follow on Twitter. Follower number is, of course, a very crude proxy of influence on Twitter, but it’s the most accessible metric for the purpose of this story.
The question of who counts as a scientist is itself a matter of debate. As a general guideline, we included only those who have completed a Ph.D. science degree and have published at least one peer-reviewed paper in a peer-reviewed journal. As an exception to this rule, we excluded professional journalists who fit the above criteria.
We recorded the number of Twitter followers, tweets, and citations for our revised list on 30 September. To tally the number of citations for each scientist, we looked up their Google Scholar profiles or, for those without a profile, used estimates produced by the Publish or Perish software, developed by business professor Anne-Wil Harzing of ESCP Europe. Due to limitations of both methods, the citation numbers are only rough estimates and likely undercount actual citations. This number is particularly problematic for certain names. For example, there’s no easy way to distinguish physicist Brian Cox of the University of Manchester in the United Kingdom from physiologist Brian Cox of the University of Toronto in Canada in calculating the former’s citation count.
The K-index is calculated as follows: In his commentary, using data gathered on 40 scientists, Neil Hall derived a formula for calculating the number of Twitter followers a scientist should have given one’s citation count. The K-index is the ratio of the scientist’s actual follower number to the follower number “warranted” by the citation count.
An Excel document with all the data collected is here.