From a weekly column on Business Etiquette: "...conducted two studies with managers and corporate recruiters to see if impressions of professionalism are tainted by references to personal life. The answer was yes." No, the answer IS yes! Since the study attempted to see if impressions ARE tainted (present tense), then the response must also be stated in present tense. Truth be known, I would have used past tense for both sentences, since the study has obviously already taken place.
Then, from later in the same column: Researchers say if more than one in five items that adorn your office are personal in nature, you may be viewed as unprofessional." NO! First, I would have used "one in five items WHICH adorn your office." But more importantly, "more than one in five items IS personal in nature," not ARE. One is a singular word. Therefore, it IS personal in nature, not ARE. We never say "One person are coming to the party tonight." We say "one person IS." Common sense, people. Common sense.