The worrying thing is that it appears to be genetic.
My daughter seemed to have all of the, errm, qualities that her mother exhibits in this area from the moment she could give me a hard stare.
She’s 10 now and, frankly, any boy who wants to go out with her later in life will have my sympathy and probably experience the almost permanent state of bemused incomprehension at what’s going on in her head that I do.
My son, when smaller, used to work on the principle that if he was pee’d off he’d try and punch you and then it was all forgotten about. He’s 15 now and seems to have resorted to the ‘perma-sulk’ approach to dealing with his parents.