The Reverse Scrolling
Apple heavily promotes a feature they call “Natural Scrolling.” This paradigm treats your trackpad (or Magic Mouse) like a touchscreen: when you push your fingers up, the content on the screen moves up (which means you scroll down the page). If you connect a standard PC mouse with a scroll wheel to your Mac, macOS automatically applies this “Natural” direction to the wheel as well. If you have spent decades using standard Windows machines where rolling the wheel down moves the page down, this automatic reversal feels entirely backwards and makes navigating documents incredibly frustrating.
Reverting to Standard Scrolling
To restore standard behavior and stop macOS from automatically changing the mouse scroll direction to the reversed “Natural” setting, you must adjust the specific hardware preferences.
Ensure your external mouse (or trackpad) is connected. Click the Apple logo in the top-left corner and select System Settings (or System Preferences). In the left-hand navigation sidebar, scroll down and click on Mouse (if you are using a trackpad, click on Trackpad). Look for the toggle switch labelled Natural scrolling. By default, this is turned on (blue). Click the toggle to turn it Off (grey). The change is instantaneous. Now, pulling your fingers down on the trackpad or rolling the mouse wheel towards you will pull the scrollbar down, moving you down the page in the traditional, expected manner.