Experimental evidence of massive-scale emotional contagion through social networks

Facebookが行った大規模な心理実験の報告

Experimental evidence of massive-scale emotional contagion through social networks
Adam D. I. Kramer, Jamie E. Guillory, and Jeffrey T. Hancock

がPNASで読める．論文の要旨は，

Emotional states can be transferred to others via emotional contagion, leading people to experience the same emotions without their awareness. Emotional contagion is well established in laboratory experiments, with people transferring positive and negative emotions to others. Data from a large real-world social network, collected over a 20-y period suggests that longer-lasting moods (e.g., depression, happiness) can be transferred through networks [Fowler JH, Christakis NA (2008) BMJ 337:a2338], although the results are controversial. In an experiment with people who use Facebook, we test whether emotional contagion occurs outside of in-person interaction between individuals by reducing the amount of emotional content in the News Feed. When positive expressions were reduced, people produced fewer positive posts and more negative posts; when negative expressions were reduced, the opposite pattern occurred. These results indicate that emotions expressed by others on Facebook influence our own emotions, constituting experimental evidence for massive-scale contagion via social networks. This work also suggests that, in contrast to prevailing assumptions, in-person interaction and nonverbal cues are not strictly necessary for emotional contagion, and that the observation of others’ positive experiences constitutes a positive experience for people.

で，Tech Crunch Japan から引用すると

この研究は、ユーザーのニュースフィードの内容が、ユーザー本人の感情形成に影響を与えるかどうかを発見することを目的とし、歪曲されたコンテンツを見た後の投稿内容のトーンを測定することによって判断するもの

であり，

70万人近いFacebookユーザーが、ポジティブあるいはネガティブに偏ったコンテンツを見せられた。研究の結果、ポジティブなニュースフィードを与えられたユーザーはよりポジティブな内容を投稿し、ネガティブなニュースフィードを与えられたユーザーはネガティブな内容を書き込んでいたことがわかった

そうなのだ．

その後実験方法についてもちろん批判が巻き起こっている．興味の有る方は山本一郎氏の記事「Facebookが豪快な社会実験でまた世界をお騒がせ」をご参考に．