What gets upvoted and downvoted on reddit? (new research) - part 1

My name is Maria Priestley and this post is based on research that was done as part of my undergraduate degree in Biological Anthropology at the University of Durham. All data were collected during November 2013 and used for nonprofit educational purposes. A published version of the findings can be found in PLoS One journal.

We all have a vague idea of the reasons why content gets rated positively or negatively on reddit, but it's always nice to get empirical evidence to explore these things. I attempted to do this using an online questionnaire consisting of two parts. Redditors were first asked to vote on a selection of 15 comments and to write brief explanations for these decisions. All explanations were then read and recurring reasons for upvotes and downvotes were identified. The second part of the survey had 29 questions asking participants to rate the importance of different content traits as influences on voting (e.g. content sounding intelligent, following reddit rules, expressing agreeable opinions...). These ratings underwent statistical analyses to group correlated traits into a smaller number of broad influences, which were then examined against variables like age, gender and reddit membership duration. The participant sample consisted of 489 adults recruited mainly from /r/TheoryOfReddit, /r/Anthropology and /r/SampleSize. I will summarise the main findings here, but there is a second instalment here containing full details on the comment voting results.

The chart below shows the average importance of different influences on upvotes and downvotes as reported by the participants.

We can see that wishing content to be seen by others was rated as the most important influence in upvotes. The other influences appear less important, but they give a better idea of the specific content traits that may contribute to upvotes and downvotes.

Informational skill was an influence that covered questions on the interestingness and intellectual value of content, so its high importance is understandable. When voting on comments, participants often explained their decisions with references to how interesting the comment was, as seen in the example below.

Common reasons for voting on other comments also included references to quality of writing and sources.

These results were interpreted in an evolutionary context as part of my undergraduate anthropology thesis. With regard to the high importance of informational value in voting, I suggested that upvotes could be a way of showing deference to people who are deemed to possess informational skill. This kind of tendency may have helped our ancestors to secure access to skilful individuals who possessed valuable information.

Relevance and compliance with subreddit rules also had reasonably high importance scores. Statistical analyses showed that the importance of these influences decreased slightly with age, and that women and participants with longer reddit membership durations gave higher scores. These differences were small but statistically significant. When writing about their voting decisions, participants often mentioned whether or not comments were relevant to the submission title.

With regard to prosociality, people tended to prefer content that was helpful and considerate of others, with rudeness or aggressiveness often eliciting downvotes. For example, a comment stating: “Don't ask for advice from reddit, it's full of the most smug self righteous assholes this side of the internet” was downvoted by 65% of participants, most of whom said that it was unhelpful or rude. This is unsurprising, given that prosocial norms are almost universal and vital across different cultures. Numerous scientists have even suggested that people may be biologically adapted to favour prosocial behaviour and to punish violators.

For unoriginality and Karma-whoring as influences in downvotes, it was found that their importance decreased slightly with age. The statistical analyses also indicated that longer-serving redditors were most averse to these traits. Average importance scores for each membership duration group are shown below.

Empathy, agreement and humour were quite important with regard to upvotes, and women gave significantly higher importance to this group of influences compared to men. The survey contained another question asking participants about the extent to which their voting is influenced by emotional reactions to content, where women also gave higher scores. Both differences are displayed in the chart below.

In the written vote explanations, participants often commented on their emotional reactions as reasons for upvoting emotive comments.

Disagreement was quite important in downvotes. The statistical procedure I used showed that people didn't give consistent levels of importance to agreement and disagreement (perhaps because downvoting in disagreement is more frowned upon and varies depending on the subreddits where one resides). Nonetheless, both agreement and disagreement were common in the written vote explanations for opinionated comments, as seen in the example below.

In my thesis I suggested that the involvement of personal opinions in upvotes and downvotes may reflect the human tendency to use rewards and punishments to enforce our cultural norms. No matter how ignoble it may seem on reddit, encouraging each other to hold similar beliefs and to behave in accordance with shared standards probably helped our ancestors to efficiently maintain complex institutions in trade, education and marriages.

Social influence, or the existing number of votes on a piece of content, was reported as being mildly important in voting. Interestingly, the importance of this influence decreased slightly with age, and younger people reported taking more notice of content that is accompanied by high numbers of votes and Gold badges.

That's it for now. As usual with this kind of research, it's hard to know if the findings are truly representative of the general voting behaviour of redditors, but I hope that these results can be useful in some way.