It's funny how boys really do seem to be drawn to typical "boy" toys... balls, cars, tools, etc. With Annabelle's girly toys being all over the place, it's not like Corgan isn't exposed to plenty of "girl" toys and non-gender-specific toys, but the boy things still seem to be his favorite. I always wondered how much of that was nature vs. environment, but I have always been very non-sexist when it comes to both Annabelle and Corgan's toys. Annabelle has generally had more girl things, because she's a girl (duh), but I've still exposed her to tools, musical instruments (I know that isn't totally "boy", but it's traditionally more boy than girl), sports equipment (again, traditionally boy), and other things. She didn't have many cars, but she also didn't seem too interested in them. I'm also totally fine with Corgan hugging Annabelle's baby dolls, playing in her kitchen, and loving gymnastics. He does like those "girl" things, but still seems to prefer the "boy" toys and activities or gender-neutral things like the barn toys.
Not too long ago I read or heard something about boys with sisters being more well-rounded, especially if they have older sisters. That didn't surprise me at all because my younger brother has two older sisters, and although he's a man's man who played baseball and basketball through school (even into college), has always dated the hottest girls, and always had a big group of "manly" male friends, at the same time he's proud to wear pink and never forgets to kiss his mom. Knowing that, it always makes me laugh to see Keith trying to refocus Corgan when he picks up a doll or mention that he needs to play football (yes, at 1 year old) to balance out gymnastics (which is really just a big indoor playground at this age). I'm all for well-roundedness, and I know that if my brother could survive being dressed up in my sister's "dolly's dress" and willingly dancing the Sleeping Beauty ballroom dance with her, then Corgan will also not have his "manliness" compromised... he'll just be more well-rounded.