What site user group permissions are needed for one site user to be able to impersonate another site user?

In order for one site user to be able to impersonate another site user, the user will need to have the following site group permissions:

The impersonate button is found next to each user in the list of site users which is found on the /settings page.  The user will need the ability to edit their account information to get to the /settings page and the ability to view a list of users to access the impersonate button.