Thankfulness is the social virtue by which we acknowledge people and their generosity. It’s not just a customary expression of thanks when someone does something nice. It means going out of your way to show people your gratitude for them going out of their way for you.
Affability is another word for approachability. It means you’re free to talk and free to help. You don’t mind people knocking on your door to tell you something. It is another social virtue that makes us put others before ourselves.
Being introverted is not an excuse to avoid these virtues. An introverted person can most certainly have a heart focused on other people, and that is what’s at the heart of the social virtues.
You may think these virtues aren’t as important as the others since they are not so explicitly mentioned in Scripture. In fact they are. Remember the parable of the lepers in Luke 17:11-19. Jesus heals ten lepers, and only one returns to thank him. Jesus asks, “Where are the other nine?”
Likewise, Jesus regularly healed those who approached him out of the blue, showing affability. Jesus showed the social virtues, and so should we.