I think every dog is different but it seems smaller dogs are more yappy. I think some dogs bark when they are bored or lonely - seems like "outdoor dogs" (don't get me started on what I think of this) bark more than those that live in homes.
I have had 3 dogs in my lifetime.
My cocker-springer mix never once barked or whined (oh how I miss him - he was like a little person in so many ways).
My boxer mix only barks when someone knocks or rings doorbell.
And then my little jack-in-the-box jackrussel-chihuahua mix barks at EVERYTHING: when he sees or hears cars go by, when any dog or person he doesn't know is anywhere he can see them, and sometimes I have no idea what he is barking at. He is getting better since I started using a dog whistle followed by a soft "quiet Sam" until he stops. Tried everything before that but this is only help that makes a dent. Of course, his barking is worse in winter, when he gets bored and stir crazy (but don't we all).
So my answer: who knows?