Science backs up the cause of being nice to fellow human beings. And come on, you've generally got to be nice to people, because being tough with them won't do you any good.
1. Being nice is the key to a happy team.

Internet giant Google held a survey to find out what factors would built a happy, productive team? Thus, Project Aristotle was formed, where the employees were asked questions based on psychological safety, dependability, structure and clarity. It was then revealed that being nice is a big factor which leads to a happy team. By letting go of ego and pride, one has to help each other by discussing how they can make the product better is the key to making productive teams.
2. Selflessness is the secret to success.

Wharton professor Adam Grant has stated in his book ‘Give and Take’ that the most successful people aren’t the ones who are selfish, but those who selflessly give the most. In his book Grant gives an example of Abraham Lincoln who unselfishly withdrew from a Senate race in the 1830s, but then he won the support of his opponent in the next election. Therefore, the key to being popular with people is being nice and giving.