You know the email. The one with the subject line, “You HAVE to watch this. Soooooo FUNNY!” Or perhaps it was something more eloquent like, “Crazy cat!” A simple mouse click is all it takes to reveal that you’ve been sent a viral video (assuming your friends and family only send you cool stuff).

As marketers, viral videos are very much a part of our lexicon, and not just the funny ones where babies do cute things. We’re talking about viral video campaigns that have thrust brands into the spotlight, securing their position as a cultural touchstone in our shared experience. And when that happens, people are more likely to take action in your favor––be it passing along your video or purchasing your product.

But how does one make a viral video? Here’s the short answer: You can’t. You can only make a video. Whatever happens afterwards determines whether or not your video can achieve the coveted status of “going viral.” There is no formulaic solution. And it’s more likely that a video of you sitting around thinking about making a viral video will go viral instead of your branded video. And you’ll be left wondering why.

But don’t fret. There is some science behind these social media enigmas, a running theme of sorts. According to Jonah Berger, assistant professor at the University of Pennsylvania’s Wharton School, the one thing viral videos have in common is that when we watch them we briefly enter a state of “high arousal.” Our heart rate increases, sweat glands open. And, it is in this heightened physiological state that we are more likely to share information.

It all goes back to our basic need as humans to foster a sense of community and solidarity. Every time you send or share a video you’ve subconsciously attached the following sentiment, “I feel ______, and I hope you feel ______, too. Let’s bond over it!”

If you can create a video that evokes such a strong feeling that it moves your audience to share it and bond over it, then you might just have a viral video on your hands. So, until Google or Apple develops a device that can quantitatively measures feelings, go with your gut. Make something that moves you. Pour your own feelings into that video, and someone will probably feel the same way you do and share it. That is, unless you’re an emotion-less robot.