The dangers of excessive self-citation

Warning: This blog contains themes of a professional ethical nature that some readers may find offensive. Intended for a mature academic audience only.

As I was spending a lazy Sunday morning, tucked up in bed fiddling with my iPad, a perky little blog came across my Twitter feed (read it here). Some rather sad data were contained within: approximately 82% of journal articles in the humanities don’t get cited (within the first five years of publication anyway) and just over a quarter (27%) of natural science articles don’t get cited either. I was actually surprised that the percentage of non-cited paper was that low, until I read down the article and noticed that the analysis didn’t include self-citations. Scientists, especially marine biologists, are particularly bad at excessively self-citing, or as I like to call it, #citurbation.

Self-citations are the guilty secret of science researchers. Let’s face it, we’ve all done it at some time. Now I’m as guilty as the next scientist – late one Friday night I’m still working and on the computer screen in front of me I have a half-done editorial and, guiltily,  I slip in a self-citation. Or in the final throes of a massive multi-authored monograph, I toss in a self-citation from left field. But why is it that marine biologists so often self-cite? Is it because of lack of attention? Biomedical articles rarely go uncited (and their journals typically have much higher impact factors). Is it because marine biology journals tend to have low impact factors and marine articles are spread across so many journals that they don’t get the same prominence (see this previous SFS blog, he says in a blatant example of self-citing)?

One reason why biomedical non-citation rates are so low might be because many labs/institutes or research groups cite each other’s work. Here is an example of a new researcher who was uncomfortable that, of the 15 citations of his lab’s work, 13 came from within the lab. This type of #citationdaisychain bumps up the impact of articles and the prestige of the lab, for those who don’t look into the citation data too closely. Journals have also been manipulating self-citations to increase their impact factors, and thus ultimately sales, to the extent of setting up citation cartels, although these manipulative journals often tend to be low ranking (see here). Manipulation of papers and citations to boost impact factors is sadly rather common, however, as mentioned in this previous blog (oops, I’m self-citing again).

But is self-citation really bad? A moderate amount of self-citation is often inevitable. But excessive self-citation can be considered rather crass and unprofessional, and in some cases is unethical.  However, in some circumstances, self-citation (even excessive self-citation) may be valid and forgivable. For example, if you are in a restricted field of research, self-citation may be unavoidable. If less than half a dozen scientists study your species or region, you’ll quickly find that you are citing each other repeatedly. Also, PhD students are expected to produce publishable works from dissertation chapters, so these publications will be linked. Self-citation is therefore inevitable in this situation, especially if post-doctoral work follows on from PhD studies. However, it is a common rookie mistake by young, ambitious academics to excessively self-cite grey literature. As a journal reviewer and editor, I frequently see manuscripts with self-citations of annual progress reports, conference presentations, newsletters and, in one impressive example, a PhD proposal. I would advise young academics to avoid this unless absolutely necessary, as it ultimately reflects badly upon the authors.

As an example of the dangers of self-citation, in my field of study there is at least one researcher (who-shall-not-be-named) who has become well-known for excessive self-citing, and, moreover, not citing relevant papers by (potentially competing) researchers. In fact, the researcher in question will typically cite their own paper, where a relevant paper is cited as a source, rather than the original journal article that contains the novel data. This is rather unethical, to say the least. Papers by this researcher are easily identified even in a double-blind review process, as the reference list largely include papers that feature one specific author, and does not mention relevant papers by other well-known academics in the field. This practice has certainly earned this researcher a bad reputation and has led to submitted manuscripts being rejected. This goes to show, that as far as comprehensive literature reviews are concerned, excessive self-citation can make you blind.


P.S. Thanks to Steven Cook for pointing out an article on this very topic – which can be found here


  1. Carolyn Thaler · January 19, 2015

    You never see the United States Supreme Court cite law review articles.
    No one reads them.

  2. Steven Cooke · January 20, 2015

    Interesting post – here is a paper that we wrote on the topic of self-citation… maybe by sharing others may cite it!?!

Comments are closed.