It seems like this has been a long time coming, but CEO Mark Zuckerberg has now confirmed that Facebook (NASDAQ:FB) is working on a counterpart to its hugely popular "Like" button. As far as features go, no one could have predicted that the deceptively simple button would have exploded in the way that it has and become an iconic part of Facebook's very fabric. The inevitable question of whether or not a "Dislike" button then makes sense has persisted for years.

In the most recent public Q&A town hall session, Zuckerberg at long last said that the social network is indeed working on such a button, and will begin testing it soon. Depending on how those tests do, Facebook could subsequently roll out a "Dislike" button on a broader scale. With over 1.5 billion monthly active users, the company knows that it has to take a measured approach to feature deployments.

A change of heart
Interestingly enough, Zuckerberg shot down the idea of a "Dislike" button less than a year ago. At a similar Q&A last December, Zuckerberg echoed his long-standing stance that Facebook wants to focus on positive social interactions:

And that's not something that we think is good for the world. So we're not going to build that. I don't think there needs to be a voting mechanism about whether posts are good or bad. I don't think that's socially very valuable or good for the community to help people share the important moments in their lives.

However, the answer was a little more nuanced, since Zuckerberg did acknowledge that Facebookers need to be able to express themselves in a wider variety of ways, particularly when sad events are shared. It just so happened that weeks after that Q&A, Facebook's "Year in Review" feature would get criticized for cheerfully reminding people about painful memories. The most prominent example was developer Eric Meyer, whose daughter died last year.

Confronting such a controversy, Facebook had no choice but to acknowledge that it can't just be cheery all the time. Perhaps this is why Zuckerberg is having a change of heart.

Empathy is key
Yet, there's a fine line that Facebook must walk. It must provide a broader set of tools for users to express themselves, but it absolutely does not want a "Dislike" button to be used as a downvoting system or vehicle for harassment. Put another way, Facebook very clearly does not want to turn into Reddit or Imgur, the two most popular sharing sites that are built on a system of upvoting and downvoting.

The overarching goal here is empathy, according to Zuckerberg. Facebook needs to provide people with a way to quickly express empathy for sometimes difficult life events. Kind of like a way of saying, "Man, that sucks" when a friend gets dumped by a significant other.

At a time when Twitter is struggling for direction on how to improve its core product, Facebook knows exactly where it needs to go with its own.

Evan Niu, CFA owns shares of Facebook. The Motley Fool owns and recommends Facebook and Twitter. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.