There's nothing quite like the feeling of logging into Facebook and getting a virtual punch to the gut when your ex's face adorns Facebook's On This Day window.

On This Day posts are nostalgia-inducing walks down your social media memory lane, and when they're happy memories, scrolling through them can be a nice reminder of how great life was a year or two or three ago. But when they bring up a memory like losing a job, the death of a loved one, or self-harm, it can trigger negative emotions or behavior.

The On This Day feature is similar to TimeHop, the standalone app that shows you a daily post history from all your different social media accounts, which rose to popularity in 2012. Facebook only shows you posts from its own social archives — status updates, photos, and posts friends made on your timeline since the beginning of your account.

Facebook's memories are different from TimeHop in that the company algorithmically decides what post to show you in your News Feed, and often those memories sit right at the top of your home feed without you deciding to click on the feature.

Facebook is a virtual scrapbook, albeit one overflowing with both trivial and important memories. Unlike a scrapbook that you pick up yourself when you want to reminisce, however, Facebook's software is making the decisions on what it thinks you should see.

According to Dr. Julia Shaw, associate professor and researcher in the department of law and social sciences at London South Bank University and author of the upcoming book The Memory Illusion: Why you may not be who you think you are, the intricacies and emotions in our real lives cannot be understood by a computer program making decisions based on Likes or comments. Including whether or not we want to relive memories stored on Facebook.

"An algorithm doesn't know which memories you actually find important. It knows how often you shared something or how many Likes it received, but it doesn't know what the complexity of your real-world life looks like," Dr. Shaw said in an email to the Daily Dot. "This means that Facebook memory prompts are far more likely than scrapbooks to have negative effects, making us rehash unwanted memories at bad times."

"Triggering" memories are ones that cause a negative emotional response. These can include memories we shared to Facebook that were, at one point, very positive experiences, such as a vacation with a person who is now your ex-partner.

The algorithm can't understand that just because something is still on Facebook, it means we want to view it again. Value changes with time, and what Facebook's technology interprets as meaningful could become an inappropriate reminder of past experiences that remain in our virtual history for any number of reasons.

Facebook knows its feature isn’t always perfect — the company has a team working on improving the algorithms and figuring out what kinds of content people care most about. Currently, the understanding of memories is based on engagement; Facebook correlates a post with a lot of Likes or comments with a positive memory.

"If the person being presented with these unwanted memory prompts is currently in a bad state, these may even have the potential to push someone over the edge into more severe problems like depression or anxiety, or can lead to negative behaviors such as fights and excessive drinking," Dr. Shaw said.

Considering most of the content we share on social media is highly-edited positive snapshots of our lives, it makes sense that Facebook would want to encourage you to relive it. Studies show that good news spreads faster and gets more engagement than bad news on Facebook, and editing yourself on Facebook can sometimes improve self-esteem. (Though the positive pruning also might come with a caveat — the pressure to live up to the perfect self-construction people present on social media can cause anxiety or stress in life offline.)

Jeff Hancock, professor in the department of communications at Stanford University, researches psychological processes in social media, and said we're still in the very early stages of understanding how social media impacts our psyche.

"We’re not very self-aware creatures yet about sharing. It goes back to our evolution — we evolved to talk face-to-face and all of our words disappearing. Our memory is designed to live in that communication environment," Hancock said in an interview with The Daily Dot. "That’s why I think people aren’t very conscious about sharing. But here’s what I think ends up happening and why I think these reminders on the whole will be positive, though they will do some negative triggering ... when people post on social media, they tend to, by the vast majority, post positive things."

Facebook provides ways of tailoring On This Day reminders so you don't relive negative posts. You can select certain people or dates in On This Day preferences, and the algorithm won't include them in your daily roundups. And by clicking on the settings of an On This Day post, you can tell Facebook to show you less of this type of content.

Additionally, Facebook doesn’t show On This Day posts from memorialized accounts (people who have passed away); people you once were “in a relationship” with on Facebook, but are no longer; and people you have blocked. A Facebook spokesperson told The Daily Dot there are no plans to implement an off-switch of sorts to avoid On This Day posts entirely.

Frequently though, we forget exact dates, and sometimes people we don't want to be reminded of aren't on Facebook; their memories just live in our own old photos. In my case, telling Facebook to show me fewer reminders didn't entirely work — they still frequently pop up at the top of my News Feed.

By only sharing snippets of my life to Facebook and then telling Facebook who and what I don't want to remember, I'm actively engineering my memory. Facebook's algorithmically-selected memories are further manipulating my forgetfulness. Dr. Shaw calls this "memory double-distortion," and said that when we use Facebook, we have the potential to engage in this behavior, which could impact our brain's recall of life events.

"The first distortion happens when we upload and filter content, socially engineering our profiles in a way that often only records the kinds of memories we think are worthy of sharing, and make our lives look great," she said. "When we then go through this engineered life and reminisce about these events, we are only reinforcing these kinds of memories. Our brains thus become better at remembering the details of things we put on Facebook, and worse for details that were originally not deemed 'share-able' enough. The memories in our brains are likely to mould with the memories on Facebook.

"We become who we pretend to be," she said.

The potential for new technologies to threaten our memories is a concern that extends all the way back to 370 BC. Socrates, the ancient Greek philosopher, worried that the written word, a new way of documenting human life, could destroy and distort memory. Socrates' argument against the alphabet was captured, in text, by Plato.

For this discovery of yours will create forgetfulness in the learners' souls, because they will not use their memories; they will trust to the external written characters and not remember of themselves. The specific which you have discovered is an aid not to memory, but to reminiscence, and you give your disciples not truth, but only the semblance of truth; they will be hearers of many things and will have learned nothing; they will appear to be omniscient and will generally know nothing; they will be tiresome company, having the show of wisdom without the reality.

Social media is in its infancy as a communication tool. Developers are still trying to create algorithms smart enough to provide positive experiences and omit terrible reminders without humans having to tailor their own memories.

Face-detection algorithms in development can discern emotions in videos and photographs and are being used by advertisers for market research. Imagine if a Facebook algorithm was smart enough to recognize the microexpressions in a photo you shared of your grandmother's funeral — it would keep it out of the self-made scrapbook, a memory quietly shoved aside in favor of a smiling selfie two years earlier.

Technologists must strike a balance between reducing harm and providing thoughtful context around historical events. At one point, the information or photo posted to social media was deemed worthy of sharing — but has time altered its significance?

Hancock said that more research needs to be done in order to better understand how and why people share one thing, but don't want to relive it.

"In this case, we have a new way of affecting our memory, and that’s probably about a core of human thing as possible, and we’re at the very beginning of how these things can change us," he said. "I think we should be doing lots of research on this to understand what kind of photos lead to positive memories. Are there indicators? Is there some set of features of a post or the context around the post that suggest that it’s something that shouldn’t be brought up again?"

Communication has evolved since the popularization of social media — things like emoji, FOMO, and Likes creeping into our daily routines — but the perception of social media has also changed. The fact that memory modification or triggering reminders is a point of contention at all shows that the lines between social media and our "real lives," have blurred.

If our posts consisted only of what we ate for breakfast, or the book we finished reading recently, the potential for harm would not be a concern.

"This is a really wonderful example of the transformative nature and the potential it has to affect people in a real way," Hancock said. "It’s no longer real life and social media is some narcissistic and trivial thing. It matters to people."

From our friends at The Daily Dot, by Selena Larson.

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