They also never talked to ex-spouses because the assumed there would be a level of extreme animosity toward the party seeking the clearance and they would say anything to get back at the person.
Wasn’t married at the time so I don’t know personally about that then. Just, they interviewed the entire family and all the neighbors as well as others from college. Seems to me they would have interviewed ex-spouses because of blackmail potentials - they were big on it then.
I heard under Clinton the whole process was reduced to a interviews by phone from a list supplied by the applicant ...