http://en.wikipedia.org/wiki/How_to_Win_Friends_and_Influenc...
Also, when in a debate or argument with someone, focus on your end goal. Which is more important - winning the argument (or saving face) or getting your objective achieved?
Much better is to learn psychology, courses are available free on Coursera, Udacity and EDx.
You can spend your time doing a psychology course, but I'm not sure that would make you a more affable person.
http://en.wikipedia.org/wiki/How_to_Win_Friends_and_Influenc...
Also, when in a debate or argument with someone, focus on your end goal. Which is more important - winning the argument (or saving face) or getting your objective achieved?