Would the habit and so the crux of 'selflessly' spending on others destroy if we start 'expecting' that it would bring happiness?
My dad recently became eternal. All his life he used to do this. I guess the compassion and selflessness which is attached with the act is what brings happiness. Though you expect nothing in return but it does pay off in form of better relations and therefore, the other person also goes out of the way to help u. Even God helps you through people or otherwise. That's my dad's magnificient life story :)
However, I am just concerned that when people would know causal effect of spending on others on your happiness then if we would start spending on others while expecting something in return, we would not be happy and also act selfish. Therefore, some variables are needed to be established. More than that, it is the act of giving which should provide us happiness and not the other things :)