It may seem like no reason to us, but the dog had some reason.
It could be something as easily overlooked as suddenly diverting your attention and energy from the dog to the new child. Dog doesn't understand, so the child becomes competition.
Like 95% of these "studies" the results are completely useless.
Exactly like studies dealing with everything else, unless it is normalized "per 1000" etc. Comparing extremely popular dog breeds to rare ones needs to take that into account...
Kinda surprised Australian cattle dogs weren't in the list. Mine is great with our 5mo but we wouldn't leave him alone with her and we always pay close attention when she gets close to him. He ignores stuff she does that would cause him to warn us off.
Australian cattle dogs are temperamental but also a somewhat rare breed ive got two and while I trust one with my life and the other to mind her own business im still iffy about the one who would try to save me. Mainly cause hes completely neurotic love the boy though.