In the brain, there are mirror neurones, these neurones copy what ever the other person near you is doing( that’s why yawning is contagious), smiling is contagious too.
An experiment done using an MRI scan, showed that when you flash a photo of someone smiling in front of another person, their brain releases dopamine( the feel good hormone).So, a while back I made a conscious effort to spread positive vibes.
I walk into my office in the hospital consciously smiling as I go. I get smiles back.There are places you never get a smile, for example, the London Underground. London people manage to infect you with their stress! Lol
When one person in the house is in a funk, they always manage to infect everyone else with the negative energy, unless you stay away from them.The big question is, what would you rather spread? Positive or negative vibes?