I’ll bet that when Hitler was a toddler, his Mum used to tickle him under the chin and say:
— ‘Who’s my favourite little boysie-woysie, eh? And won’t you promise your old Mumsy-wumsy you won’t invade Poland when you’re a big boy?’
— ‘I pwomise’. (But in German, of course: ‘Ich pwomise’.)
Similarly, Jack the Ripper was cute as a button at four years old. His chin was constantly being tickled by every passing beldam in Whitechapel:
— ‘Aww, so cutesy-wootsy! Such a goody-woody ickle boy!’
You see how chin-tickling, combined with mawkish nursery babble, can have deadly consequences, though they may lie dormant for many years.
Think of the suffering that could have been avoided if these infants had had a manly father-figure to give them clear, unsentimental instruction:
— ‘Don’t touch Poland and never hit a woman. Got it, son?
— ‘Got it, Dad. Any chance of a tickle?’