“The word kindness does the following:

1-It brings up thoughts of donating to charity, holding open doors for strangers, helping out colleagues with their work. One aspect that unifies most kind acts is that they are effortful. However, effort is aversive—humans and other animals generally avoid it. So why are we kind if it requires so much work? Ourselves and other researchers have shown that people are indeed willing to put in physical effort to help other people. We don’t do so as often as when our effort benefits us instead, but we will do it, particularly if the benefit for the other person is large.”

Research shows that specific parts of the brain represent how effortful an act is and these are linked to overcoming the hard work needed to help others. Next time we are faced with the opportunity to help, it is important to focus on the benefits, rather than the effort, to motivate us that being kind is worthwhile.

2-Another essential aspect of being kind is being able to learn that what we did helped another person. Research has shown that when we are learning to help someone else, there is a part of the brain in the cingulate cortex that increases its activity only when we are being kind to someone else, and not when we are helping ourselves. This suggests that we might have specific parts of the brain for being kind.

3-One factor that affects all of us is age, and this has come up in recent research as important for kindness too. Older people seem to be more willing to be kind, whether that is putting in effort for others, learning about rewards, donating to charity, and even engaging in higher daily step counts to help. Older people seem to be more kind than younger people, on average. However, who we are being kind to is also a critical predictor of our willingness to help.

4-Age seems to be an important factor in being kind to others. But, at any age, are there particular traits that affect our kindness? Several researchers have shown that an important difference between people is levels of what are known as psychopathic traits—lack of empathy, remorse, and guilt.

Both when we are putting in effort to help others and when we are learning whether we have helped someone or not, our ability to be kind seems to vary on a spectrum with our levels of psychopathy. However, on the flip side, people who are higher in empathy are faster at learning how their actions help others and more willing to put in effort to help. Cultivating our levels of empathy, and minimizing any traits linked to psychopathy, are therefore essential for the tendency to be kind”

Psychology Today (5 Core Lessons from the Science of Kindness | Psychology Today Australia)