TagLast edit: 15 Sep 2021 12:16 UTC by Pablo

LessWrong (sometimes spelled Less Wrong) is a community blog and forum dedicated to improving epistemic and instrumental rationality.


In November 2006 the group blog Overcoming Bias was launched, with Robin Hanson and Eliezer Yudkowsky as its primary authors (Hanson 2009). In early March 2009, Yudkowsky founded LessWrong, repurposing his contributions to Overcoming Bias as the seed content for this “community blog devoted to refining the art of human rationality” (Alexander 2014; Bloom 2019a). This material was organized as a number of “sequences”, or thematic collections of posts to be read in a specific order, later published in book form (Yudkowsky 2015). Shortly thereafter, Scott Alexander joined as a regular contributor.

Around 2013, Yudkowsky switched his primary focus to writing fan fiction, and Alexander launched his own blog, Slate Star Codex, to which most of his contributions were posted. As a consequence of this and other developments, posting quality and frequency on LessWrong began to decline (Alexander 2017). By 2015, activity on the site was a fraction of what it had been in its heyday (Bloom 2019b).

LessWrong was relaunched as LessWrong 2.0 in late 2017 on a new codebase and a full-time, dedicated team (Vaniver 2017; Bloom et al. 2019). The launch coincided with the release of Yudkowsky’s book Inadequate Equilibria, posted as a series of chapters and also released as a book (Yudkowsky 2017). Since the relaunch, activity has recovered and has remained at steady levels (Bloom 2019b; cf. Sempere 2021: “the conclusion that the LW community recovered from its previous decline holds”).


Alexander, Scott (2014) Five years and one week of Less Wrong, Slate Star Codex, March 13.

Alexander, Scott (2017) Comment on ‘A history of the rationality community?’, Reddit, August 15.

Bloom, Ruben (2019a) A brief history of LessWrong, LessWrong, May 31.

Bloom, Ruben (2019b) Data analysis of LW: activity levels + age distribution of user accounts, LessWrong, May 14.

Bloom, Ruben et al. (2019) Welcome to LessWrong!, LessWrong, June 14.

Hanson, Robin (2009) About, Overcoming Bias.

Monteiro, Chris et al. (2017) History of Less Wrong, LessWrong Wiki, October 20.

Sempere, Nuño (2021) Shallow evaluations of longtermist organizations, Effective Altruism Forum, June 24.

Smith, Justin E. H. (2019) Irrationality: A History of the Dark Side of Reason, Princeton, New Jersey: Princeton University Press.

Vaniver (2017) LW 2.0 open beta live, LessWrong, September 20.

Yudkowsky, Eliezer (2015) Rationality: From AI to Zombies, Berkeley: Machine Intelligence Research Institute.

Yudkowsky, Eliezer (2017) Inadequate Equilibria: Where and How Civilizations Get Stuck, Berkeley: Machine Intelligence Research Institute.

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