From October of '06 to August of '07, I worked with the Indian Navy. They bought one of our old ships (USS Trenton LPD-14...you can do a google search on this). I was working closely with on Senior Master Chief and I noticed that when I was explaining something he would bounce...well 'bounce' isn't the right word, sort of a light roll...his head. I wasn't sure if there was something wrong with him or not. A lady I dealt with for work told me her step father was Indian and I asked about this thing that the Master Chief did. She explained that he was, in essence saying, "I see what you're saying, and I understand." So, I guess it's a culture thing.