This section gives you step by step instructions on how to slow down the mouse in macOS 12 Monterey, with pictures of the screens to help.
1. Click the Apple icon in the top left corner of the screen and choose System Preferences from the menu.
2. In the System Preferences window, click Mouse.
3. On the Mouse preferences screen, Apple Magic Mouse users can only change the tracking speed. To change the scrolling speed, Apple Magic Mouse users need to follow step 4. Non-Apple mouse users can change both the tracking speed, and the scrolling speed on this screen.
Apple Magic Mouse: Adjust the slider for Tracking speed to change how quickly the pointer moves.
Non-Apple mouse: Adjust the slider for Tracking speed to change how quickly the pointer moves. Adjust the slider for Scrolling speed to change how quickly pages scroll.
4. Click the Apple icon in the top left corner of the screen and choose System Preferences from the menu.
4. In the System Preferences window, Select Accessibility.
5. In the sidebar, scroll down and select Pointer Control. On the right, if not already selected, select the Mouse & Trackpad tab.
6. Click the Mouse Options button.
7. Adjust the slider for Scrolling speed to change how quickly pages scroll.
8. By default, scrolling uses an inertia effect. With this effect enabled the page carries on scrolling a little further after you stop scrolling the mouse. To disable this effect, select the drop-down menu next to Scrolling and select without inertia.
9. If you would prefer to disable scrolling, untick the checkbox for Scrolling.
10. Click the OK button to save your changes.
11. When you are happy with your settings, close System Preferences by clicking the Close button (red circle) in the top-left corner of the window or using the Cmd + W keyboard shortcut.
Note: If this does not work it could be because your computer settings are managed by someone else (an IT department or administrator for example). If so, you will need to contact them to access these settings or for help.