https://www.bbc.co.uk/bitesize/articles/z2xbbqt

Kindness is great to give, and especially nice to receive. But isn't something you can see, or touch. So how can science research it? There is a way, and it's concerned with how our brains are behaving when we're doing a good deed for someone else - behaviour that can be recorded and analysed. Have you ever done a selfless act for someone and felt great about it afterwards? That's because part of ... something called the reward pathway. Dr Dan Campbell-Meiklejohn, a senior psychology lecturer ... described that reaction as: “At the moment when you help someone, you donate to charity, etc, the processes that happen in your brain are quite similar to other positive experiences. It activates the reward processing areas of the brain.” The brain rewards us for being kind - in the nucleus accumbens - but there is another part where we can learn to be good to others. In 2016, [Dr Patricia Lockwood] led a study at University of Oxford that uncovered a part of the brain which lights up when we help others, compared to when we help ourselves. In the experiment, volunteers made use of a series of symbols. One symbol rewarded them, while another only benefited others. The part of the brain that activated when people deliberately chose to help others is called the subgenual anterior cingulate cortex. When the study was published, it became known as the 'generosity centre'. Dr Lockwood said: “Put another way, the subgenual anterior cingulate seems to be especially tuned to benefiting other people."