6.2.1 Emotional Contagion

700,000 Facebook users were put into an experiment that may have altered their emotions. The participants did not give consent and the study was not subject to meaningful third-party ethical oversight.

For one week in January 2012, approximately 700,000 Facebook users were placed in an experiment to study “emotional contagion,” the extent to which a person’s emotions are impacted by the emotions of the people with whom they interact. I’ve discussed this experiment in chapter 4, but I’ll review it again now. Participants in the emotional contagion experiment were put into four groups: a “negativity-reduced” group, for whom posts with negative words (e.g., sad) were randomly blocked from appearing in the News Feed; a “positivity-reduced” group for whom posts with positive words (e.g., happy) were randomly blocked; and two control groups, one of the positivity-reduced group and one for the negativity-reduced group. The researchers found that people in the positivity-reduced group used slightly fewer positive words and slightly more negative words, relative to the control group. Likewise, they found that people in the negativity-reduced condition used slightly more positive words and slightly fewer negative words. Thus, the researchers found evidence of emotional contagion (Kramer, Guillory, and Hancock 2014); for a more complete discussion of the design and results of the experiment see chapter 4.

After this paper was published in Proceedings of the National Academy of Sciences, there was an enormous outcry from both researchers and the press. Outrage around the paper focused on two main points: (1) participants did not provide any consent beyond the standard Facebook terms of service and (2) the study had not undergone meaningful third-party ethical review (Grimmelmann 2015). The ethical questions raised in this debate caused the journal to quickly publish a rare “editorial expression of concern” about the ethics and ethical review process for the research (Verma 2014). In subsequent years, this experiment has continued to be a source of intense debate and disagreement, and the criticism of this experiment may have had the unintended effect of driving this kind of research into the shadows (Meyer 2014). That is, some have argued that companies have not stopped running these kinds of experiments—they have merely stopped talking about them in public. This debate may have helped spur the creation of an ethical review process for research at Facebook (Hernandez and Seetharaman 2016; Jackman and Kanerva 2016).