“Learn to do common things uncommonly well; we must always keep in mind that anything that helps full the dinner pail is valuable.” ― George Washington Carver
What does it mean to be a responsible traveler? It means much more than just traveling light, recycling plastic bottles or even reusing your hotel bath towels. Those things are great first steps but being a responsible traveler is a "heart action".
A socially responsible traveler has a heart for people. He/she ensures that negative social, economic and environmental impacts are minimized and that positive footprints that enhance economic benefits for local people and host communities are the only thing left behind.
Bottom line, a social responsible traveler is a global citizen and ambassador for humanity.