How to get people to comment on your posts

In a 2012 study at Harvard, people gave up about 17 percent of the money they could have earned so they could answer questions about themselves instead of questions about someone else. A comment is a person doing exactly that, in public, on your post.

I've always been the one hitting the follow button. What got me into studying how people behave on social media was realizing that the accounts I followed were run by people, and so was mine, and the people following me were people too. People want to feel knowledgeable, included and important, and a comment section is where you can see whether a post gave them any of the three. The three studies below are about the last two.

People give up money to talk about themselves

Diana Tamir and Jason Mitchell set up a task where, on every round, people chose between answering a question about themselves or answering one about another person or a fact, for slightly more money. The payments were one to four cents a round. People kept picking themselves, and in that version of the task they gave up about 17 percent of what they could have earned. In another version, they also gave up money to have their answer shared with someone else.

The same paper scanned people's brains while they answered. Talking about themselves produced more activity in part of the brain's reward system, an area called the nucleus accumbens, than judging another person did.

For a post, that means the question people answer most readily is one about them: what they've tried, which of two they'd pick, what happened when they did something. A question about your product asks them to talk about you.

Answer where the next person can see it

Davide Proserpio and Georgios Zervas followed Texas hotels on TripAdvisor from 2001 to 2013 and compared each hotel's ratings before and after it started replying to reviews in public. To rule out a hotel simply getting better, they used the same hotels' Expedia reviews, where hotels rarely replied, as the comparison. After hotels started replying, their ratings went up 0.12 stars and they got 12 percent more reviews.

The detail that matters most for a comment section: the effect showed up when the replies sat on the first page of reviews, where the next guest would see them, and not when they'd been pushed to page two. The authors' reading is that replies tell future reviewers the business is listening, so more of them speak up.

Being ignored lowers belonging

In a 2024 experiment, researchers in Italy put 212 university students on a mock social network where every other account was a computer program. At random, some got six likes on their profile and the rest got one. The students who got one like scored much lower on belonging, self-esteem, sense of control and the feeling that their existence mattered (an average of 3.21 against 4.92 on the study's scale), and they reported more negative emotion. The task took about three minutes.

Someone who comments on your post and hears nothing back is in the position of the students who got one like.

Where the research stops

• Tamir and Mitchell's participants shared with a friend or relative they'd brought along, not with a business, and I couldn't find a published direct repeat of the study.
• The hotel study is about reviews of a stay, not comments on a post, and it's observational, so it shows what happened after hotels replied rather than proving the replies caused it. Later studies of hotel replies have found mixed results.
• The like experiment measured the person posting, with likes only, in a short lab task.
• None of the three tested whether more comments raise your reach. What the platforms do say is that comments and replies are among the things they predict: Instagram's Explore page lists the chance you'll comment, and Threads lists the chance you'll reply. Their own pages are linked below.

What to do on your next post

• Ask about them, not about you. "What did you try first?" or "Which of these two would you pick?" is a question about the follower. "What do you think of my new product?" is a question about you.
• Make the answer short enough to type with a thumb. A choice between two things, or one word about their own experience.
• Reply to every comment, including the one-word ones, and reply on the post rather than in DMs, so the next person scrolling sees that you answer.
• Reply with something about them. Use what they said, and where it fits, ask one more question about it.

Comments are one signal. Sends are another, and they work by a different mechanism: why people send your post to someone. For what the platforms say they measure overall, see how the ranking works.

Sources: Tamir & Mitchell (2012); Proserpio & Zervas (2017); Sacino et al. (2024); Instagram Explore ranking; Threads feed ranking. Every study was read in full before it was cited here.