Watch these recommended TED-Ed lessons and TED Talks:

Why do we love? A philosophical inquiry
Ah, romantic love; beautiful and intoxicating, heart-breaking and soul-crushing... often all at the same time! If romantic love has a purpose, neither science nor psychology has discovered it yet – but over the course of history, some of our most respected philosophers have put forward some intriguing theories. Skye C. Cleary outlines five of these philosophical perspectives on why we love.

A brief history of melancholy
If you are a living, breathing human being, chances are you have felt sad at least a few times in your life. But what exactly is melancholy, and what (if anything) should we do about it? Courtney Stephens details our still-evolving understanding of sadness -- and even makes a case for its usefulness.

How to practice emotional first aid
We sustain emotional injuries, like failure or rejection, just as often as we do physical ones like cuts and colds. There are science based techniques we can use to treat emotional injuries that can help soothe the distress they cause and prevent them from impacting our short and long-term psychological well-being. Guy Winch makes the case for practicing emotional hygiene— taking care of our emotions, our minds, with the same diligence we take care of our bodies.

Inside OKCupid: The math of online dating
When two people join a dating website, they are matched according to shared interests and how they answer a number of personal questions. But how do sites calculate the likelihood of a successful relationship? Christian Rudder, one of the founders of popular dating site OKCupid, details the algorithm behind 'hitting it off.'