It's generally referred to (in my experience) as "theory" or "historical theory". It is usually a part of most historians' frame of thinking. It's more concerned with the "why" of history than the "what" of history, or the underlying reasons events happened and continue to happen rather than the details of the events themselves. Most other similar disciplines have some sort of theory subfield, such as archaeology or anthropology. These theories are often controversial, and represent the efforts of a historian or group of historians (or archaeologists or anthropologists) to explain trends they see in human behavior over time. These theories are an important part of the work of historians, since they attempt to provide reasons for events happening, and a structure within which to frame and study history.

If you are interested in studying these ways of understanding history, check out the journal History and Theory.

This website from the University of Virginia has a good overview and some additional resources.

This is sometimes called "universal history." It is not in vogue because it requires making massive generalizations. The more common trend in the academy today is microhistory, the in-depth study of small periods of time, heavily localized, and using those insights to make generalizations not on all of history but relatively bounded topics (e.g. how gender and politics intersected in pre-Revolutionary France, as revealed by the diaries of lady so and so).

I would not call any of this 'scientific' and would be dubious of anyone who claimed to be.