My boy is a bit older, 17 months and thinks it's hilarious to smack mummy. he also lashes out at me if he doesn't get his own way. it makes me so sad and i think he hates me! in every other aspect he is a delightful child, very affectionate and pleasant, just has moments of being a total brat. we have been saying a firm 'no' but it has mixed effects tbh. mostly he just! laughs but once or twice he has bawled his head off (and i felt horrible too!) i was reading a toddler behaviour book and it suggested that at 18months they don't really understand the negative attention and just see it as attention from mummy. they suggested ignoring it for the time being until they're old enough to understand. it's a difficult one, because i'm inclined to believe everything i read whereas my husband thinks a lot of stuff is bunkum and we should be giving him a tap on the hand (i would weep!). i am saying no in a neutral voice at the minute and saying 'no that hurtsmummy' but tbh, i don't know what effect it has. and we've not even hit the terrible twos yet!!