I have been constantly impressed by how early kids start to pick up reasoning, and how reasonable some of their parents are.
I was once in an Italian café in South Kensington where an elegant mum was persuading her little boy to have some salads.
‘Mum is telling you these vegetables are absolutely delicious.’ (my note: they really are! yummy!)
‘How do I know you are right?’ (see? reasoning)
‘Well, mum is generally right.’ (see? reasonable)