With the advent of touch screen, the natural scrolling seems more intuitive as the user is directly interacting with the page. If you imagine the scroll wheel sitting on a paper you were reading, the reverse scrolling direction is intuitive - the content moves in the direction the wheel would push it. And the first scrolling mouse had physical wheels (many still do). The first trackpad scrolling mimicked how mouse scrolling worked. So the same metaphor was adopted for scrolling wheels to keep consistency.
For arrow keys, metaphor used was to scroll the viewport which seems more natural (By pressing down, users can view the content below and vice-versa). A Little Historyīefore the addition of scrolling wheels to the mouse, page could be scrolled through keyboard buttons-cursor arrow keys or mouse interacting with the scroll bar. Another way to look at reverse scrolling is that the user is interacting with the scrollbar, rather than the page.
