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.[1] 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."[2][3]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.[4] 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.[5] By 2015, activity on the site was a fraction of what it had been in its heyday.[6]

LessWrong was relaunched as LessWrong 2.0 in late 2017 on a new codebase and a full-time, dedicated team.[7][8] The launch coincided with the release of Yudkowsky's book Inadequate Equilibria, posted as a series of chapters and also released as a book.[9] Since the relaunch, activity has recovered and has remained at steady levels.[6][10]

In 2021, the LessWrong team became Lightcone Infrastructure, broadening its scope to encompass other projects related to the rationality community and the future of humanity.[11]

Further reading

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

LessWrong. Official website.

Donate to LessWrong.

AI Alignment Forum | Effective Altruism Forum | Lightcone Infrastructure | rationality community

  1. ^

    Hanson, Robin (2009) About, Overcoming Bias.

  2. ^

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

  3. ^

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

  4. ^

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

  5. ^

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

  6. ^
  7. ^

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

  8. ^

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

  9. ^

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

  10. ^

    "the conclusion that the LW community recovered from its previous decline holds" (Sempere, Nuño (2021) Shallow evaluations of longtermist organizations, Effective Altruism Forum, June 24)

  11. ^

    Habryka, Oliver (2021) The LessWrong Team is now Lightcone Infrastructure, come work with us!, LessWrong, September 30.