The out of the box Yes / No column type in SharePoint just displays a checkbox with no text next to it. If you are using it in a survey then you have biased the question as the field is either pre-unchcecked or pre-checked. (and it defaults to YES!)
The workaround? Just use a Choice field with two choices “Yes” and “No”. When used in surveys the end result is exactly the same as Yes/No and it defaults to neither choice selected.
And, you can be more verbose when needed: “Yes I agree” / “No I don’t agree”.
Both a normal Yes/No and the Choice Yes/No in a survey (or list) form.
The survey report:
