Genia Kenrick
Genia Kenrick voted up Matt Radiance's answer

Several reasons:

-Sign of thinking (Some people do it automatically while they are thinking deeply)

-Sign of stress & fear (some people do it automatically in stress times just like tabbing foots on the ground ect . . )

-People also do that for posing in shooting pictures ect . .

-Just a wrong habit (some people … Read more