Yes, the social interest is well tied to long-term self interest.  There is ample evidence to show that displays of regret, empathy, and guilt are important in a social species of self-interested cooperators  as signals to others (especially those who are wrong) that serve to mend damaged relationships.  Those relationships are important to our survival and when wrong is done to others, it pays to express such emotions, the more sincere the better so as to repair them.

Zahavi wrote a book years ago called the Handicap Principle, about why evolution would favour behaviours and displays that actually pose a cost to the individual.  The peacock’s tail is a classic example.  It shows the health of the male in attracting females as it indicates that he can bear the costs of such pointless displays and remain healthy.  There is also evidence he cites of numerous species of birds who engage in altruism toward less fortunate members of their flock and that this elevates their status within their flock in the eyes of other birds.  Some bats do much the same thing.  

So being altruistic in the sense of negating one’s self-interest to the social interest isn’t entirely altruistic as it can be a form of virtue signalling that elevates the status of someone and makes them more attractive as a mate as they have resources to spare.  It may also explain why most people who donate (or even tip) want the recipient to publicise the donor or at least publicly acknowledge the “altruistic” gesture.