Smiling is contagious. Laughing is contagious. Even if you don’t know what someone is laughing at wholeheartedly, we often find ourselves starting to smile or giggle, just because hearing others laugh so much make us want to laugh too.
In other words witnessing others smiling or laughing sincerely, raises our spirits. When someone is having a bad day or a difficult time, a warm smile to them can be exactly what they need to know you care, a gift of love and compassion.
The Distinct Dot 