"One of the keys to a long-lasting relationship may be simply the ability to notice when your partner is elated, even if you're not feeling particularly happy at the moment."

How do you keep a romantic relationship healthy and strong over the long haul? Research suggests that the way we respond to our partners' emotional states may be particularly important. As discussed in the video below from our friends over at The Science of Us, a new study suggests that the more sensitive we are to a partner's positive emotions in particular--even when we aren't in a good mood ourselves--the better off our relationships tend to be.

Check out the video to learn more. For additional details regarding this research, you can find the full study here.