A Boy Thing?

In a project that my internal dialogue calls 'The Further Adventures of Daddy and J', I am using at least a day a week of my extended paternity leave to take J somewhere interesting. At seven months of age, he's not particularly aware of each place, but he seems to have fun and that's what counts. Our most recent trip: Tate Britain.

An older lady (OL) stops us to have a chat with J. I think it's because I put him forward facing. 

OL: Do you think it's a boy thing?
Me: Eh?
OL: What he's doing... with his feet.

I look down and witness the same view of J that I see most minutes of the day. Once again, he has pulled his socks off and is holding his feet. This is nothing new to me.

OL: My daughter, she never played with her feet, but my son wouldn't leave then alone.
Me: Her feet?

She looks puzzled (I couldn't resist taking such a golden opportunity to deliberately misunderstand)

OL: (missing my joke) No, his own feet. And now all these years later, his son does the same. I think it must be a boy thing.
Me: Oh, he's always pulling his socks off. That's what babies do, don't they? Mind you, he does pick things up with his feet.
OL: Really?
Me: He holds a toy up quite comfortably and then uses his hands to play with it.
OL: My goodness.

By her expression, this appears to be the most wondrous thing in the world. I could understand if she was still talking directly to J, but she isn't.

Me: I think his Grandad started him off doing that.
OL: Well there we are - knowledge passed on down the male line.
Me: (joking) You never know, perhaps there's a gene for it.
OL: Maybe...

We leave it at that. I think I may have inadvertently given credence to her theory.