[tremendulo]

People implicitly praise and blame by their emotional responses. A negative response from a person you admire or seek to emulate is felt negatively whether it was intended as blame or not.

Reward and punishment are an amplification of a generally unwanted signal. I'm not advocating these; I'm not taking a moral stance. Rather I'm talking about what people already do irrespective of what they think or say they are doing.

Children learn language because it helps them to get what they want. If reward and punishment guaranteed results then adults would be able to reliably recite the multiplication tables (which they can't).