Ask yourself why whenever someone invites you for a coffee you feel the need to also invite them in the future? Or when a friend does a favor for you feel the need to return the favor later. This is called the principle of reciprocity.
We are programmed to return the favor or reciprocate, this is one of the most important principles for happiness and influencing others explained by Robert Cialdini in his book Influence The Psychology of Persuasion.
In a study published in the Journal of Applied Social Psychology researchers tested the effects of mint giving in restaurants. Turns out there is a psychology behind mint giving. When waiters gave mint along with the check, the tip increased by 3% and interestingly when the waiters gave mints with the check AND came back with more mints the tip increased 21%
So what does this mean? Not only does reciprocity influence people but also it was even more powerful by following up or having a genuine concern for the person!
There is another side to though, although reciprocity is a researched and proven principle of influencing others you need to keep something in mind, be careful with your expectations, my advice is to give without expecting anything in return, of course relationships are a two way street, but if you give just because you WANT to give you will be happier and feel like a better person in the process.
Unfortunately, there is no exercise to practice this, you basically have to start doing it, and believe me you will start seeing the world differently and people will look at you differently, those around you will see that you are genuine and kind.
“Carry out a random act of kindness, with no expectation of reward, safe in the knowledge that one day someone might do the same for you.” -Princess Diana