I laugh at very akward times. Especially when I'm nervous. People are always asking me what I'm laughing at.....then I proceed to punch them in the face for questioning my sanity.
chuckling is a way to ward off your insecurity...kinda like people who say just kidding after everything they say. You need to get in touch with yourself and evaluate in every situation what you felt when you chuckled, what you thought and what the outcome was. Take a notebook and write down as many incidences of this as you can so you can figure out what your own "chuckle triggers" are and learn new coping skills to deal with your own uncertainty and insecurity. Good luck!
I know it's a psychological problem, but people like that bug me.