flawless shaving, bones, bends and all. venus swirl. ♪ ♪ that's one of the oldest most hotly contested debates in psychology. does it make a difference whether you're the firstborn or last born child? >> a new survey has studied $500 500,000 kids. >> reporter: the idea that our intelligence and personalities are preprogrammed simply by where we fall in relation to our siblings siblings the firstborn, a responsible leader who usually follow the rules. hillary clinton and beyonce.