Researchers have been trying to find the secrets to a good relationship. A study looked at various couples and then six years later checked in to see how they were doing.
The study, carried out by James Cordova, professor of psychology at Clark University in Massachusetts, separated the couples into two categories: 'masters' and 'disasters'.
Masters made it six years into their relationship and were happy, but disasters had separated or were unhappy.
Researchers noted how one half of a couple would tell the other about something they liked - in what they termed as an 'emotional bid'.
The bid is made in the hope that their partner would show an interest, helping to build a connection between them.
Kindness is key
Masters all had one thing in common: they responded positively to bids. Turning towards the emotional bid validates the other person, the research said. Turning away from the bid denies forming a connection.
Couples who stayed together reacted positively to bids 87 per cent of the time.
Masters would scan their environment for things they could both appreciate, whereas disasters would focus on their partner's mistakes.
It all comes down to kindness; It's the most important predictor of satisfaction, the study said. Kindness and giving creates an upwards spiral of love and generosity.
Develop your kindness like you would a muscle, the study concluded. Respond positively to bids and be kind to each other.