Kindness, the small acts of assistance and consideration for others is, I think, an inherent part of human nature just as much as aggression and competition. Very small children often display acts of kindness.
Usually we see kindness as a small voluntary almost reflexive gesture of assistance to a stranger but of course it includes good manners which in essence tell us how to be kind and considerate to others (Unless the manners become rigid etiquette.)
Good manners and kindness extend to friends and family as well as strangers. We can often forget to say thank you and be kind to our closest family from habit or frequency of cohabitation. Still a thank you is often really valuable.
Kindness gives the receiver help and a positive feeling to get through a difficulty. Just opening a door for someone makes them feel good and gives us positive feedback. Very often the small kindnesses recognise the bridge or connection between us all. We recognise our common humanity and the knowledge that we feel the same at different times.
Very often the benefit flowing to the beneficiary is out of all proportion to the cost of the small act to the giver and we are all glad of a little help from time to time
After a small act of kindness we gain for ourselves a positive feeling. It is very good for our health because good deeds release serotonin and oxytocins which over time improve our life, health and longevity. A small act of kindness has also been shown scientifically to reduce our own anxiety as indeed it does for the receiver of a kind act. Kindness has also been shown to reduce inflammation.
Kindness then is better than any feel good medication.
So we should choose to be kind. Although deliberate actions to help our own well being are really not kindness, which is spontaneous, still if we practice some thing for own benefit it helps the receiver and we soon do so out of habit. Just as good manners are taught to children by their parents but become ingrained in later times.
A recent article in the New Scientist makes the case that nurture, kindness and altruism arose as an evolutionary by-product of warm bloodedness* so we cannot help but be kind, it is basic to our nature.
"Wherever there is a human being, there is an opportunity for a kindness." -Lucius Annaeus Seneca
President, U3A Clarence
* Professor Patricia Churchland Why Do We care? (New Scientist 28 September 2019)