New Delhi, Jan. 30 -- What if the key to a strong, happy relationship wasn't just communication or shared values-but something as simple as a smile? New research suggests that the way couples synchronise their smiles could be a powerful indicator of relationship satisfaction.

A recent study published in Emotion revealed that couples who experience greater relationship happiness tend to have better smile synchrony-that is, they smile together more often and in a more coordinated way. In contrast, couples seeking therapy for relationship distress showed significantly lower levels of smile alignment.

We all know that emotions play a huge role in our relationships and when partners feel emotionally in tune with one another, it creates a sen...