Suppose I didn't know your child's gender. The behaviour you described would not sound particularly male or female to me, given my biases. On the other hand, I infer that for you this appears to be typically "boyish" behaviour, and you use this as evidence of strong in-born gender traits. I.e. my daughter does exactly the same thing, but I didn't consider it "girlish". More "babies are duuuumb."
One interesting thing about raising an infant is that everyone seems to project different things on to the child, and to have different interpretations of the same events. For instance, my wife and I focus on the fact that our daughter seems strong and smart. Others keep telling us how pretty she is.
If she makes certain facial expressions, friends tell us it means one thing, while various relatives all have their own interpretations, that differ from our own interpretation.
I don't think your observations confirm anything except your own biases. In case that sounds harsh, I think this is true of all of us.
Note that I'm not making the strong claim that there are no gender differences. I just observe that there's much larger variation between individuals than between genders. Finally, I observe that parents treat girls and boys subtly differently even from before birth, and that this can't help but have an effect on their development.
http://www.dailymail.co.uk/news/article-1196183/Why-boys-pic...
I try to accept these differences and go with them as a parent, not ignore them or spend my time blaming society. I don't think they are incompatible with the hopes and dreams I have for my daughter. I don't think a preference for dolls means my daughter has to be a waitress instead of an engineer.
He's not hostile or asocial or anything, but he'd much rather hit his head on something, cry, and crawl right back over to try again in 5 minutes. Note that we know it's not a matter of being dumb, because there are other things like that he learns from. He's just... a boy. I think perhaps boys could fit into the "pet" template a bit longer, since girls are more humanly social, earlier, on average. (He's perfectly within normal parameters for his age and gender; he loves people, plenty of eye contact, etc., but girls are definitely different on average.)