How do cameras affect kids behavior?

It really depends on the child

if it is a shy child, they will be:

quiet

try their best to stay out of reach of the camera

very weary about were the camera is at all time

act completely normal, so that camera will not see them as odd one out

if they are confident and loud then..:

wants all the attention

making every effort for camera to be on them

loud

sorry if not enough but that is all i can think of atm.