Martyn Green

The top 50 science stars of Twitter

 Genomicist Neil Hall sparked an online tempest this summer by proposing a “Kardashian Index,” or K-index—a comparison of a scientist’s number of Twitter followers with their citations. Scientists with a high score on the index, named after the reality TV star Kim Kardashian, one of the most popular celebrities on the social media platform, should “get off Twitter” and write more papers, suggested Hall, who works at the University of Liverpool in the United Kingdom.

Though Hall says he meant his K-index lightheartedly, his article in Genome Biology sparked a Twitter storm of criticism. So just who are the Kardashians of science, and is Hall’s criticism justified? Hall tactfully declined to provide a K-index for anyone specific, but Science was curious about the names and the numbers. We have compiled a list of the 50 most followed scientists on the social media platform and their academic citation counts—and calculated their K-index by drawing on citation data from Google Scholar (A fuller explanation of how we compiled the list is below, at the end of the full story).

The top three science stars of Twitter:

(Based on followers)
  • Neil deGrasse Tyson

    1. Neil deGrasse Tyson, Astrophysicist
    2,400,000 followers @neiltyson
    Citations: 151 K-index: 11129
    Total number of tweets: 3,962
    Hayden Planetarium, United States

  • Brian Cox

    2. Brian Cox, Physicist
    1,440,000 followers @ProfBrianCox
    Citations: 33,301 K-index: 1188
    Total number of tweets: 10,300
    University of Manchester, United Kingdom

  • Richard Dawkins

    3. Richard Dawkins, Biologist
    1,020,000 followers @RichardDawkins
    Citations: 49,631 K-index: 740
    Total number of tweets: 19,000
    University of Oxford, United Kingdom

See the full top 50 list.

Rather than identifying “Science Kardashians”—those who are, as Hall put it, “famous for being famous”—the top 50 list reveals that a majority of the science Twitter stars spend much, if not all, of their time on science communication. For them, Twitter popularity can amplify their efforts in public outreach. A case in point is Neil deGrasse Tyson, director of the Hayden Planetarium in New York City and host of the science TV show Cosmos: A Spacetime Odyssey. With more than 2.4 million followers and fewer than 200 citations, the astrophysicist is undoubtedly the top-ranking celebrity scientist on Twitter—and has the highest K-index of anyone on the list. Yet few would consider his Twitter fame unwarranted.

Although the index is named for a woman, Science’s survey highlights the poor representation of female scientists on Twitter, which Hall hinted at in his commentary. Of the 50 most followed scientists, only four are women. Astronomer Pamela Gay of Southern Illinois University, Edwardsville, whose more than 17,000 Twitter followers put her 33rd on the list, says the result doesn’t surprise her because society still struggles to recognize women as leaders in science. Female scientists are also more likely to face sexist attacks online that can discourage their participation, she adds. “At some point, you just get fed up with all the ‘why you are ugly’ or ‘why you are hot’ comments.”

Twitter stardom need not exclude research achievements, as our top 50 Twitter list shows. Many have thousands of citations and seven of the people listed also appear on two recent citation-based rankings of influential scientists, the 2014 Thomson Reuters Highly Cited Researchers list and Scholarometer’s top 100 authors ranking. Even so, most high-performing scientists have not embraced Twitter. Science sampled Twitter usage among 50 randomly chosen living scientists from the Scholarometer list. Only a fifth of the scientists have an identifiable Twitter profile.

Even some who do dislike the medium. Chad Mirkin of Northwestern University in Evanston, Illinois, the highest ranking chemist on Scholarometer’s list, considers Twitter a waste of precious time that he’d much prefer spending on reading and writing scientific papers. “A lot of social media is … time spent aggrandizing one’s accomplishment,” says Mirkin, who registered on Twitter just to keep up with his son’s tennis scores. The linguist Noam Chomsky, the most famous living scientist by some measures, has also repeatedly criticized social media for reducing serious public discourse to, well, 140 characters.

So why do the highly cited researchers who are also Twitter science stars make the time to engage in social media? Geneticist Eric Topol of the Scripps Research Institute in San Diego, California (17th place; 44,800 followers), who boasts more than 150,000 citations, says he once thought the social media platform was only for “silly stuff” like celebrity news. Then he tried Twitter during a TEDMED conference in 2009, as a tool to gauge reactions to his talk. Now, he starts his workday browsing through his Twitter feed for news and noteworthy research in his field. During the day, he checks Twitter several times and spends another 10 to 20 minutes on an evening roundup. “It actually may be the most valuable time [I spend] in terms of learning things that are going on in the world of science and medicine,” says Topol, who reciprocates by daily tweeting papers, presentations, and more to his followers.

Psychologist Daniel Gilbert of Harvard University (36th; 15,500 followers) views Twitter as a natural extension of his other public outreach efforts, which include hosting the PBS science documentary, This Emotional Life. For him, Twitter is a virtual classroom connecting netizens worldwide who are interested in the psychology of happiness. “It’s another teaching tool,” he says.

Like Topol, Jonathan Eisen of the University of California, Davis (25th; 24,900 followers), says he did not start out as a Twitter fan. An enthusiast of open access and exchange, Eisen participated in scientific discussion forums, such as newsgroups, even before the days of the World Wide Web. But Twitter’s 140-character word limit initially seemed both “arbitrary and useless” to him, he says. It was for purely coincidental reasons—checking out details of a visit by famed cyclist Lance Armstrong to Davis, California—that the microbiologist signed up for an account in 2008.

But after 20 minutes of perusing news on the social media platform that day, Eisen says, he was hooked. “In a minute, I can skim through a hundred Twitter posts. … It’s pretty amazing for getting a feel of what’s going on,” says Eisen, who now daily spends anywhere from 5 minutes to 8 hours on Twitter, in addition to running a blog. Yet Eisen also has close to 42,000 citations under his belt.

Eisen says that consistently tweeting ongoing research at his lab has helped attract graduate students as well as two grants for science communication. He suggests an active social media presence might even aid applications for research funding, as it demonstrates a commitment to public outreach. But the spontaneity of Twitter can backfire, too. Eisen, for one, has live-tweeted brusque criticism at academic conferences that came back to bite him. “You can seem like a jerk, an idiot, or both,” he says.

The temporal, attention-grabbing nature of Twitter posts also makes them ill-suited for nuanced, in-depth scientific discussions. Gilbert says he prefers to tweet materials that appeal to a general audience, rather than complex scientific papers. Likewise, Eisen reserves lengthy discussions for old-fashioned phone calls and uses Twitter to instead link to blog posts and other, longer materials.

Still, he and others credit Twitter as a crowdsourcing platform for new ideas and research. Topol says he relies on the “army of Web crawlers” on Twitter to bring him the latest, most noteworthy research in medical science. His own tweets, mostly about papers and presentations he finds interesting, also form an archive that can be extracted with a little tech savvy.

The social media tool also functions as “another dimension of peer review,” Topol says. Instead of waiting for the old letters to the editor, scientists can go to Twitter for rapid critique of their research. “Authors who are not willing to get engaged on social media are missing out on a significant opportunity,” he says.

The K-index gets it wrong by suggesting that science communication and research productivity are incompatible, says Albert-László Barabási, a network theorist at Northeastern University in Boston who studies social media. Research on altmetrics—alternative metrics for measuring scientific impact—has found no link between social media metrics such as number of tweets and traditional impact metrics such as citations, he says. “We should really not mix the two … because they really probe different aspects of a scientist’s personality.”

For his part, Hall says others have read too much into his satire, which originated after seeing conference organizers factor Twitter follower numbers into speaker considerations. “I don’t mean to criticize anyone for having a lot of Twitter followers,” he says. “My criticism is only of using it as a metric on research scientists.”

It might be premature, in any case, for the scientific community to worry about “Science Kardashians” when it faces a more pressing challenge of staying relevant in public discussions. Even Tyson’s Twitter popularity is dwarfed by that of the real Kim Kardashian, who boasts 10 times as many followers.


The list of most followed scientists compiled here is far from scientific. To identify Twitter science stars, we began with celebrity scientists such as Tyson and checked out which scientists they followed. We also referenced online lists of scientists to follow on Twitter, such as this one by The Huffington Post. If we’ve missed someone who belongs on the top 50 list, do let us know in the comment section. 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. degree and 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 for our list on 15 September. To tally the number of citations for each scientist, we over the past month 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. 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. Seven on our top 50 list appear on either the 2014 Thomson Reuters Highly Cited Researchers list (*) or the Scholarometer’s top 100 authors (+) ranking, and each is noted with a symbol.

The Kardashian Index is calculated as follows: In his commentary, using data gathered on 40 scientists, 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.

 The top 50 science stars of Twitter

Read the full story on this list.
  • Neil deGrasse Tyson

    1. Neil deGrasse Tyson, Astrophysicist
    2,400,000 followers @neiltyson
    Citations: 151 K-index: 11129
    Total number of tweets: 3,962
    Hayden Planetarium, United States

  • Brian Cox

    2. Brian Cox, Physicist
    1,440,000 followers @ProfBrianCox
    Citations: 33,301 K-index: 1188
    Total number of tweets: 10,300
    University of Manchester, United Kingdom

  • Richard Dawkins

    3. Richard Dawkins, Biologist
    1,020,000 followers @RichardDawkins
    Citations: 49,631 K-index: 740
    Total number of tweets: 19,000
    University of Oxford, United Kingdom

  • Ben Goldacre

    4. Ben Goldacre, Physician
    341,000 followers @bengoldacre
    Citations: 1,086 K-index: 841
    Total number of tweets: 47,300
    London School of Hygiene & Tropical Medicine, United Kingdom

  • Phil Plait

    5. Phil Plait, Astronomer
    320,000 followers @BadAstronomer
    Citations: 254 K-index: 1256
    Total number of tweets: 47,000
    Bad Astronomy, United States

  • Michio Kaku

    6. Michio Kaku, Theoretical physicist
    310,000 followers @michiokaku
    Citations: 5,281 K-index: 461
    Total number of tweets: 1,130
    The City College of New York, United States

  • Sam Harris

    7. Sam Harris, Neuroscientist
    224,000 followers @SamHarrisOrg
    Citations: 2,416 K-index: 428
    Total number of tweets: 2,600
    Project Reason, United States

  • Hans Rosling

    8. Hans Rosling, Global health scientist
    180,000 followers @HansRosling
    Citations: 1,703 K-index: 384
    Total number of tweets: 2,708
    Karolinska Institute, Sweden

  • Tim Berners-Lee

    9. Tim Berners-Lee, Computer scientist
    179,000 followers @timberners_lee
    Citations: 51,204 K-index: 129
    Total number of tweets: 542
    Massachusetts Institute of Technology, United States

  • P.Z. Myers

    10. P.Z. Myers, Biologist
    155,000 followers @pzmyers
    Citations: 1,364 K-index: 355
    Total number of tweets: 25,400
    University of Minnesota, Morris, United States

  • Steven Pinker

    11. Steven Pinker, Cognitive scientist
    142,000 followers @sapinker
    Citations: 49,933 K-index: 103
    Total number of tweets: 1,612
    Harvard University, United States

  • Richard Wiseman

    12. Richard Wiseman, Psychologist
    134,000 followers @RichardWiseman
    Citations: 4,687 K-index: 207
    Total number of tweets: 22,400
    University of Hertfordshire, United Kingdom

  • Lawrence M. Krauss

    13. Lawrence M. Krauss, Theoretical physicist
    99,700 followers @LKrauss1
    Citations: 10,155 K-index: 120
    Total number of tweets: 1,548
    Arizona State University, United States

  • Atul Gawande

    14. Atul Gawande, Surgeon/public health scientist
    96,800 followers @Atul_Gawande
    Citations: 13,763 K-index: 106
    Total number of tweets: 2,118
    Harvard University, United States

  • Oliver Sacks

    15. Oliver Sacks, Neurologist
    76,300 followers @OliverSacks
    Citations: 13,883 K-index: 83
    Total number of tweets: 746
    New York University, United States

  • Dan Ariely*

    16. Dan Ariely*, Psychologist/behavioral economist
    73,000 followers @danariely
    Citations: 16,307 K-index: 76
    Total number of tweets: 1,091
    Duke University, United States

  • Eric Topol*

    17. Eric Topol*, Geneticist
    44,800 followers @EricTopol
    Citations: 151,281 K-index: 23
    Total number of tweets: 4,966
    The Scripps Research Institute, United States

  • Brian Greene

    18. Brian Greene, Theoretical physicist
    38,700 followers @bgreene
    Citations: 11,133 K-index: 45
    Total number of tweets: 191
    Columbia University, United States

  • Marcus du Sautoy

    19. Marcus du Sautoy, Mathematician
    34,200 followers @MarcusduSautoy
    Citations: 1,461 K-index: 77
    Total number of tweets: 3,555
    University of Oxford, United Kingdom

  • Sean Carroll

    20. Sean Carroll, Theoretical physicist
    33,200 followers @seanmcarroll
    Citations: 14,208 K-index: 36
    Total number of tweets: 7,295
    California Institute of Technology, United States

  • Robert Winston

    21. Robert Winston, Fertility scientist
    31,900 followers @ProfRWinston
    Citations: 7,324 K-index: 43
    Total number of tweets: 445
    Imperial College London, United Kingdom

  • Bruce Betts

    22. Bruce Betts, Planetary scientist
    28,500 followers @RandomSpaceFact
    Citations: 91 K-index: 155
    Total number of tweets: 1,619
    The Planetary Society, United States

  • Carolyn Porco

    23. Carolyn Porco, Planetary scientist
    26,100 followers @carolynporco
    Citations: 2,717 K-index: 48
    Total number of tweets: 12,700
    Space Science Institute, United States

  • Sebastian Thrun+

    24. Sebastian Thrun+, Computer scientist
    25,200 followers @SebastianThrun
    Citations: 57,110 K-index: 17
    Total number of tweets: 185
    Stanford University, United States

  • Jonathan Eisen*

    25. Jonathan Eisen*, Biologist
    24,900 followers @phylogenomics
    Citations: 41,289 K-index: 19
    Total number of tweets: 46,100
    University of California, Davis, United States

  • J. Craig Venter

    26. J. Craig Venter, Genomicist
    23,500 followers @JCVenter
    Citations: 75,338 K-index: 15
    Total number of tweets: 365
    J. Craig Venter Institute, United States

  • Vaughan Bell

    27. Vaughan Bell, Neuroscientist
    23,500 followers @vaughanbell
    Citations: 821 K-index: 63
    Total number of tweets: 10,900
    King's College London, United Kingdom

  • Robert Simpson

    28. Robert Simpson, Astronomer
    21,500 followers @orbitingfrog
    Citations: 2,280 K-index: 42
    Total number of tweets: 11,500
    University of Oxford, United Kingdom

  • Michael E. Mann*

    29. Michael E. Mann*, Meteorologist
    20,900 followers @MichaelEMann
    Citations: 15,049 K-index: 22
    Total number of tweets: 20,000
    Pennsylvania State University, United States

  • Jerry Coyne

    30. Jerry Coyne, Biologist
    19,500 followers @Evolutionistrue
    Citations: 16,657 K-index: 20
    Total number of tweets: 7,711
    University of Chicago, United States

  • Gary King*

    31. Gary King*, Statistician
    19,400 followers @kinggary
    Citations: 36,311 K-index: 16
    Total number of tweets: 3,080
    Harvard University, United States

  • Mike Brown

    32. Mike Brown, Astronomer
    18,300 followers @plutokiller
    Citations: 7,870 K-index: 24
    Total number of tweets: 9,764
    California Institute of Technology, United States

  • Pamela L. Gay

    33. Pamela L. Gay, Astronomer
    17,800 followers @starstryder
    Citations: 238 K-index: 71
    Total number of tweets: 12,700
    Southern Illinois University, Edwardsville, United States

  • Jean Francois Gariépy

    34. Jean Francois Gariépy, Neuroscientist
    17,700 followers @JFGariepy
    Citations: 153 K-index: 82
    Total number of tweets: 3,231
    Duke University, United States

  • Bob Metcalfe

    35. Bob Metcalfe, Computer scientist
    16,400 followers @BobMetcalfe
    Citations: 424 K-index: 55
    Total number of tweets: 16,100
    University of Texas, Austin, United States

  • Daniel Gilbert+

    36. Daniel Gilbert+, Psychologist
    15,500 followers @DanTGilbert
    Citations: 26,752 K-index: 14
    Total number of tweets: 1,294
    Harvard University, United States

  • Daniel Levitin

    37. Daniel Levitin, Neuroscientist
    15,400 followers @danlevitin
    Citations: 5,688 K-index: 22
    Total number of tweets: 3,036
    McGill University, Canada

  • Andrew Maynard

    38. Andrew Maynard, Environmental health scientist
    15,300 followers @2020science
    Citations: 10,411 K-index: 18
    Total number of tweets: 16,200
    University of Michigan Risk Science Center, United States

  • Paul Bloom

    39. Paul Bloom, Psychologist
    15,100 followers @paulbloomatyale
    Citations: 14,135 K-index: 16
    Total number of tweets: 1,973
    Yale University, United States

  • Matt Lieberman

    40. Matt Lieberman, Neuroscientist
    14,500 followers @social_brains
    Citations: 12,763 K-index: 16
    Total number of tweets: 3,088
    University of California, Los Angeles, United States

  • Seth Shostak

    41. Seth Shostak, Astronomer
    14,500 followers @SethShostak
    Citations: 424 K-index: 48
    Total number of tweets: 294
    SETI Institute, United States

  • Daniel MacArthur

    42. Daniel MacArthur, Genomicist
    14,100 followers @dgmacarthur
    Citations: 6,884 K-index: 19
    Total number of tweets: 15,600
    Harvard Medical School, United States

  • John Allen Paulos

    43. John Allen Paulos, Mathematician
    14,000 followers @JohnAllenPaulos
    Citations: 1,489 K-index: 31
    Total number of tweets: 4,144
    Temple University, United States

  • Ves Dimov

    44. Ves Dimov, Immunologist
    13,900 followers @DrVes
    Citations: 211 K-index: 58
    Total number of tweets: 32,200
    University of Chicago, United States

  • Simon Baron-Cohen

    45. Simon Baron-Cohen, Psychopathologist
    13,600 followers @sbaroncohen
    Citations: 84,132 K-index: 8
    Total number of tweets: 119
    University of Cambridge, United Kingdom

  • Amy Mainzer

    46. Amy Mainzer, Astronomer
    13,600 followers @AmyMainzer
    Citations: 1,444 K-index: 31
    Total number of tweets: 2,221
    Jet Propulsion Laboratory, United States

  • Brian Krueger

    47. Brian Krueger, Genomicist
    12,500 followers @LabSpaces
    Citations: 154 K-index: 58
    Total number of tweets: 36,700
    Duke University, United States

  • Karen James

    48. Karen James, Biologist
    12,200 followers @kejames
    Citations: 1,007 K-index: 31
    Total number of tweets: 61,800
    Mount Desert Island Biological Laboratory, United States

  • Michael Eisen

    49. Michael Eisen, Biologist
    11,800 followers @mbeisen
    Citations: 68,785 K-index: 8
    Total number of tweets: 16300
    University of California, Berkeley, United States

  • Micah Allen

    50. Micah Allen, Neuroscientist
    11,600 followers @neuroconscience
    Citations: 81 K-index: 66
    Total number of tweets: 21,900
    University College London, United Kingdom

Correction, 17 September, 12:22 p.m.: Some affiliations and areas of expertise have been corrected.