Do twitter or facebook activity influence scientific impact?

Are scientists smart when they promote their work on social media? Isn’t this a waste of time, time which could otherwise be spent in the lab running experiments? Perhaps not. An analysis of all available articles published by PLoS journals suggests otherwise.

My own twitter activity might best be thought of as learning about science (in the widest sense), while what I do on facebook is really just shameless procrastination. It turns out that this pattern holds more generally and impacts on how to use social media effectively to promote science.

In order to make this claim, I downloaded the twitter and facebook activity associated with every single article published in any journal by the Public Library of Science (PLoS), using this R-script here. PLoS is the open access publisher of the biggest scientific journal PLoS ONE as well as a number of smaller, more high impact journals. The huge amount of data allows me to have a 90% chance of discovering even a small effect (r = .1) if it actually exists.

I should add that I limited my sample to those articles published after May 2012 (which is when PLoS started tracking tweets) and January 2015 (in order to allow for at least two years to aggregate citations). The 87,649 remaining articles published in any of the PLoS journals offer the following picture.


There is a small but non-negligible association between impact on twitter (tweets) and impact in the scientific literature (citations): Pearson r = .12, p < .001; Spearman rho = .18, p < .001. This pattern held for nearly every PLoS journal individually as well (all Pearson r ≥ .10 except for PLoS Computational Biology; all Spearman rho ≥ .12 except for PLoS Pathogens). This result is in line with Peoples et al.’s (2016) analysis of twitter activity and citations in the field of ecology.

So, twitter might indeed help a bit to promote an article. Does this hold for social media in general? A look at facebook reveals a different picture. The relationship between facebook mentions of an article and its scientific impact is so small as to be practically negligible: Pearson r = .03, p < .001; Spearman rho = .06, p < .001. This pattern of only a tiny association between facebook mentions and citations held for every single PLoS journal (Pearson r ≤ .09, Spearman rho ≤ .08).


In conclusion, twitter can be used for promoting your scientific work in an age of increased competition for scientific reading time (Renear & Palmer, 2009). Facebook, on the other hand, can be used for procrastinating.

Wanna explore the data set yourself? I made a web-app which you can use in RStudio or in your web browser. Have fun with it and tell me what you find.

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Peoples BK, Midway SR, Sackett D, Lynch A, & Cooney PB (2016). Twitter Predicts Citation Rates of Ecological Research. PloS one, 11 (11) PMID: 27835703

Renear AH, & Palmer CL (2009). Strategic reading, ontologies, and the future of scientific publishing. Science (New York, N.Y.), 325 (5942), 828-32 PMID: 19679805

Why are ethical standards higher in science than in business and media?

Facebook manipulates user content in the name of science? Scandalous! It manipulates user content in the name of profit? No worries! Want to run a Milgram study these days? Get bashed by your local ethics committee! Want to show it on TV? No worries. Why do projects which seek knowledge have higher ethical standards than projects which seek profit?

Over half a million people were this mouse.

Just as we were preparing to leave for our well-deserved summer holidays this year, research was shaken by the fall-out to a psychological study (Kramer et al., 2014) which manipulated Facebook content. Many scientists objected to the study’s lack of asking for ‘informed consent’, and I think they are right. However, many ordinary people objected to something else. Here’s how Alex Hern put it over at the guardian:

At least when a multinational company, which knows everything about us and controls the very means of communication with our loved ones, acts to try and maximise its profit, it’s predictable. There’s something altogether unsettling about the possibility that Facebook experiments on its users out of little more than curiosity.

Notice the opposition between ‘maximise profit’ which is somehow thought to be okay and ‘experimenting on users’ which is not. I genuinely do not understand this distinction. Suppose the study had never been published in PNAS but instead in the company’s report to share holders (as a new means of emotionally enhancing advertisements), would there have been the same outcry? I doubt it. Why not?

Having issues with TV experimentation versus scientific experimentation?

Was the double standard around the Facebook study the exception? I do not think so.  In the following youtube clip you see the classic Milgram experiment re-created for British TV. The participants’ task is to follow the experimentor’s instructions to electrocute another participant (who is actually an actor) for bad task performance. Electro shocks increase in strength until they are allegedly lethal. People are obviously distressed in this task.

Yesterday, the New Scientist called the classic Milgram experiment one of ‘the most unethical [experiments] ever carried out’. Why is this okay for TV? Now, imagine a hybrid case. Would it be okay if the behaviour shown on TV was scientifically analysed and published in a respectable journal? I guess that would somehow be fine. Why is it okay to run the study with a TV camera involved, not when the TV camera is switched off? This is not a rhetorical question. I actually do not grasp the underlying principle.

Why is ‘experimenting on people’ bad?

In my experience, ethical guidelines are a real burden on researchers. And this is a good thing because society holds researchers to a high ethical standard. Practically all modern research on humans involves strong ethical safe guards. Compare this to business and media. I do not understand why projects seeking private gains (profit for share holders) have a lower ethical standard than research. Surely, the generation of public knowledge is in the greater public interest than private profit making or TV entertainment.

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Kramer AD, Guillory JE, & Hancock JT (2014). Experimental evidence of massive-scale emotional contagion through social networks. Proceedings of the National Academy of Sciences of the United States of America, 111 (24), 8788-90 PMID: 24889601

Milgram, S. (1963). Behavioral Study of obedience The Journal of Abnormal and Social Psychology, 67 (4), 371-378 : doi: 10.1037/h0040525

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picture: from http://www.geripal.org/2014/07/informed-consent-in-social-media.html