NEW YORK (TheStreet) -- Conventional psychology recognizes six basic emotions. Soon, Facebook (FB) - Get Report will as well.

The social network will begin rolling out a new feature, "Reactions," that adds six new emoji alternatives to its "like" button. It will allow users to respond to posts with love, laughter, happiness, surprise, sadness and anger in addition to its standard thumbs-up.

"It expands the vocabulary people have to respond in quick, light-weight ways," said Andrea Forte, assistant professor at the College of Computing and Informatics at Drexel University, in an email to TheStreet. "It makes it easy and uncomplicated to signal, 'hey, that's so sad your dog died.' That's good news for people who post about things they are struggling with."

"Reactions" will initially be tested in just two locales -- Ireland and Spain, starting today. The company's director of product, Adam Mosseri, told

TechCrunch

the markets were selected because both have large national user bases without extensive international friend groups (and thus work better as closed test groups) and allow Facebook to see how the mechanism works among both English-speaking and non-English speaking users.

There have long been rumblings of the inclusion of a "dislike" button into the Facebook interface, which Facebook CEO Mark Zuckerberg addressed in a September town hall Q&A, telling the audience, "We're working on it."

At the same event, he discussed the nuances of building such a "surprisingly complicated" feature and deciphering what emotions it was that users really wanted to articulate. "What they really want is to be able to express empathy," he said. "Not every moment is a good one, right?"

The feature may have a positive impact on those who go online for support when bad things happen to them, making it what Forte called a "win" for Facebook users. She pointed out that "Reactions" will be a boost for Facebook's data science as well.

It's worth noting that Facebook isn't the first entity to expand the range of emotions with which it allows users to react to its content. Real-time messaging platform Slack lets users react to messages with emojis, and news website BuzzFeed allows readers to respond to posts with reactions like LOL, win, OMG, cute, fail and WTF.

"Although 'Reactions' expands the ways Facebook users can respond quickly to a post, it also creates a more controlled vocabulary that Facebook can use to understand what people's responses are to items in their news feed," she said. "People respond in all kinds of ways right now -- using stickers for example -- but it's hard to interpret what it means when someone responds to a post with a dinosaur driving a convertible. 'Reactions' can help feed the system with responses that are less ambiguous and may help support functionality like content ranking."

Facebook's dealings with users' emotions and the conclusions drawn from data gathered on them have proven tricky in the past.

It came under harsh criticism in 2014 when a research paper  revealed it had conducted a massive psychological experiment on nearly 700,000 users by manipulating their news feeds to determine emotional impact. Adam D.I. Kramer, one of the paper's authors and a researcher at Facebook, posted a detailed explanation of the study and apologized for the unease caused. "In hindsight, the research benefits of the paper may not have justified all of this anxiety," he wrote.

Facebook appears to have learned from past mistakes in keeping users in the dark on its emotions-related testing. On Thursday, product manager Chris Tosswill outlined in a post how the reactions test will impact rankings on news feeds. "Our goal is to show you the stories that matter most to you in News Feed. Initially, just as we do when someone likes a post, if someone uses a Reaction, we will infer they want to see more of that type of post," he wrote. "We will spend time learning from this initial rollout and iterate based on findings in the future."

Beyond making Facebook more emotional, some could perceive the move as a way to make the network more "millennial" through the use of emojis. The Cassandra Report, an ongoing study of emerging trends and generational insights, reported by The New York Times, found that four in 10 millennials would rather communicate in pictures than in words.

But according to Claire Wardle, research director at the Tow Center for Digital Journalism at Columbia University, its appeal is broader. "Emoji use isn't limited to millennials at all. Emoji use has grown considerably," she said in an email to TheStreet. "Emojis make communication over mobile very easy, much easier than typing on the move. So as mobile use as grown, emoji use has grown too."

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.