Social media are an integral part of the social landscape of teens today. This seems to have happened overnight, and now we are faced with some difficult questions: What does it mean if teens spend more time interacting via social media and less time interacting face to face? Should we be concerned that teens post suicidal thoughts on blogs rather than talking directly to parents and friends – or just feel relieved that they are telling someone? Is there a problem with the fact that, for many teens, it seems ok to break up a romantic relationship over text?

The short answer to these types of questions is: We have no idea. Scientists know next to nothing. Policy makers are shooting in the dark. Pundits and talking heads and techno-sages have a lot to say, but no basis upon which to draw conclusions. Yet these questions are incredibly important given the growing ubiquity of social media.

As a scientist and mother of two, I am particularly interested in the impact of computer-mediated social exchanges on kids’ social and emotional development. I think this is a major public health and social policy issue that has only begun to be addressed – at least in a way that is backed up by scientific evidence. Some may say these questions are alarmist, but others may ask why it’s taken us so long to ask them. Whatever the case, we need answers.

My intuition is that computer-mediated interactions and social media will create a world in which lots of good things can happen – social movements can blossom, people who feel lonely can feel more connected, and people who already have a rich social network can better stay in touch with their loved ones. And things I can’t even imagine will be the norm when my young children are teens. My own 3-year-old is already completely at ease with technology, and I am quite certain that he will find it natural to connect with others in computer-mediated ways.

But my intuition is also that something has fundamentally changed, and that social media represent a way of connecting that is different from how we evolved. We evolved to talk to each other face to face, to share emotions in real time, and to interpret even extremely subtle signs of emotion in the faces, voices, and bodies of our social partners. These experiences are also the basis upon which our “emotional brains” develop normally. That is, without these experiences, we cannot develop the empathy, emotional sensitivity, and ability to control our emotions that are fundamental to being human.

If social media increasingly replace face-to-face interactions, then kids today may have fewer opportunities to build these basic social and emotional skills. Skills like empathy require that we are emotionally sensitive enough to see that someone is upset, that we take the time to put ourselves in their shoes, and that we offer support. If we are busy posting, texting, and tweeting our thoughts and experiences, do we have less time and ability to support others and in turn receive support?

A recent study suggests perhaps so. Published in the January edition of Evolution and Human Behavior, the team of researchers from the University of Wisconsin found that when girls stressed by a test talked with their moms, stress hormones dropped and comfort hormones rose. When they reached out to their moms via IM, however, nothing happened. By the study’s physiological measures, IM’ing with their moms was barely different than not communicating with them at all. The authors concluded, in aninterview with Wired – “people still need to interact the way we evolved to interact.”

It’s very important to note that interacting in ways that differ from how we interacted a hundred thousand or even a hundred years ago isn’t a bad thing. We didn’t evolve to drive cars, or have penicillin. And the modern world is unthinkable without a vast array of technological advances that are evolutionarily new.

But some think that social media may indeed be derailing our emotional evolution. A survey study by Konrath and colleagues published in 2010 suggests that college students today (“Generation Me”) have less empathy and are more selfish than students 20 years ago. Researchers conjecture that social media may be the culprit…. but there is little direct evidence to support this.

In my lab, we are trying to unravel such possibilities. For example, in a study we will soon submit for publication, we showed that college students who use more social media are less emotionally sensitive to faces – they don’t interpret emotional facial expressions as accurately as those who use less social media.

In this study, we used a computerized facial morphing task in which neutral faces gradually “morph” into mad, sad, or happy faces. This task is meant to measure emotional sensitivity, because to do the task well you need to be able to correctly identify very subtle signs of emotion in the face. We found that people who are frequent Facebook users (more than 8 hours a week) made more mistakes when they were asked to identify happy faces than infrequent users (less than 4 hours a week).

So, this finding might mean that by using Facebook frequently, we are becoming less sensitive to emotion – happiness in particular. But it could also mean that people who are already a little less sensitive to subtle emotional expressions choose to use more social media. Importantly, these are correlational data, so we can’t draw strong conclusions about cause and effect.

For this reason, it is crucial to conduct research that can actually get at cause and effect. I have just such a project in the works. The plan is to follow teens from the time they are 13 until they are 17. I’ll track what types of social media they use, how often they use them, why they use them, and if they prefer social media to face-to-face interactions for doing certain things (like sharing emotional experiences). Then I’ll test how these patterns of social media use directly influence changes in teens’ emotional strengths and weaknesses over time– their empathy, emotional sensitivity, their brain functioning, and how well they control their emotions.

By scientifically tracking teens over time, we can start to unravel whether social media drive our emotional lives, whether social media just reflect the way we already are, or whether both are the case. Without research that considers all these possibilities, we just can’t know which is true.

Social media are social tools like any other, right, neither good nor bad? – happy people can use them to share ideas and experiences; troubled people can seek out healthy or destructive social connections; bad people can find victims; and the socially awkward can find a safe haven.

Or maybe social media are very special indeed, and will have a profound impact on how we live as social and emotional beings. This is the question I am most interested in. I think we all embrace the idea that social media will change us in some way. And now, we must spend time, energy and resources to figure out exactly how.