because they're not boys!

This conversation occurred this past Sunday.

Katie:  Anden, who did you play with at Church today?

Anden:  Hmmmm...Shem.

Katie:  Who else?

Anden:  And Asher.

Katie:  What about Rachel or Katie or Addison?

Anden:  No, just Shem and Asher.

Katie:  Why not the girls?

Anden:  We don't like to play with girls, Mom.  Just boys.

Katie:  Oh really?!  Why don't you like to play with girls?  

Anden:  Because, Mom, (quite exasperated at this point)--girls are just not boys!  (I can imagine him thinking "DUH!")

Is this supposed to start so young?  Where does he get this stuff?!