What do you think about Christopher Hitchens' argument that women aren't funny (See details)?

I have read this article a few times over the past few years and its argument always comes up empty. I admire several female comedians (as long as they aren’t joking solely about girly things) like Sarah Silverman (who I think has crossed over into the boys’ club because of her ability for dick jokes and ironic racism) and….well, that’s the only one who comes to mind at present. Deep down in my gut I feel like maybe men are funnier, but another part of me screams, “No! Women can be equally as funny!”

I don’t want to believe women aren’t funny. Help me out here.