my son i 5 nearly 6 and has such low self esteem,no matter how often i praise him he reacts badly for example
he comes home with a certifiicate i tell him how good that is and he tears it up and says its rubbish,this applies to nearly everything he does any praise is met with a bad reaction but i would feel bad if i didnt praise him,even on his birthday last yr when all his freinds sang happy birthday he got up and left the room and went in a huff on the stairs i just dont know what to do with him and this is now causing a big prob at school were any praise for good work results in him ripping it up and going in a mood,also now my 3 yr old daughter is copying him thinking this is the right way to react

does anyone have any ideas of how to build his self esteem and confidence?