John sat and stared into the fire, a small frown dinting his brow. Opposite him Sherlock had retreated into his Mind Palace, storing away all that he had learned recently.
Into the companionable silence John cleared his throat and spoke.
"You're very good at reading people Sherlock, how soon do you think those character traits develop?"
Slipping back into the 'real world', the younger man opened his eyes, giving the question consideration.
"I would think from the day a child is born, why?"
"Oh I dunno, I was thinking about the kids in the home I suppose. The manager told me that currently the fifteen children in care range between four and twelve years, and I just wondered…."
"At the age of four I knew I wanted to be a scientist, admittedly I hadn't decided what sort of scientist but it was enough to be getting on with."
"Hmmm, I thought so." Flicking a glance at Sherlock, he added "You know, Sally may have been onto something."
"How so?"
"Hamleys are providing loads of toys and gadgets, but apparently the children will expect Santa to choose their gift…. I thought maybe…."
"I could play 'elf' and deduce what each child would prefer?"
"You wouldn't have to dress up…." John looked hopeful.
"An interesting experiment…" Sherlock smiled suddenly. "Let the challenge begin!"