Dear Curious: Interesting question. “My first reaction was, ‘why not say happy birthday?'” says Doug Schade, a principal consultant at recruiting and staffing firm WinterWyman. “After all, if the hiring manager put his or her date of birth on a LinkedIn profile, it’s public information. So what harm could it do to mention it?”

Of course, with everyone Googling everyone else these days, and checking out each other’s LinkedIn and Facebook profiles, it’s easier than it’s ever been to gather lots of details about people. A new poll from executive job board TheLadders.com says that 62% of job seekers study up on interviewers before meeting them, while just 35% research only the company. “No interviewer is likely to be surprised that you’ve looked up his or her LinkedIn profile,” Schade says. “In fact, it’s expected.”

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Still, on second thought, Schade recommends skipping the birthday wishes. The reason is one that he says many job seekers overlook. “A job interview is different from an ordinary conversation that you might have with anyone else, because it is hemmed around with legal issues,” Schade notes. “Certain topics are off-limits for an interviewer, by law. If you bring up any of them, you risk putting that hiring manager in an awkward position.”

Age is among the factors — along with race, ethnicity, religion, marital or family status and, in some places, sexual orientation — that interviewers have to steer clear of, so job candidates should, too. “Besides, some people don’t like birthdays,” Schade adds. “They’d prefer not to be reminded that they’re having one.”

At the same time, the most successful job interviews are those that spark some personal connection. The trick is to find one that’s unrelated to anything protected by law, and that’s not always easy.

For instance, let’s say an interviewer has photos of his kids all over his office, and they happen to look about the same age as yours. You might remark, “Cute kids!” but you’d be wise to leave it at that. Since interviewers generally aren’t allowed to ask you how many children you have or how old they are — on the theory that the answers could affect their perception of how distracted (or not) you might be as an employee — don’t volunteer the information.

So what kinds of personal stuff are okay to bring up? “Don’t forget, any hiring manager is wondering, ‘Would I enjoy working with this person every day?’” Schade points out. “So try to find some common ground, where you connect with the interviewer in some way beyond just business. But keep it to neutral topics like a sports team you both follow.” If by chance you grew up in the same state, went to the same college, belong to the same trade association, or have mutual acquaintances, those are all fine fodder for small talk, too.

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What if you just can’t dig up anything you have in common with the person who’s interviewing you? Not to worry. There are plenty of other ways to wow interviewers. A recent survey by staffing firm OfficeTeam asked 650 human resources executives to recall what job candidates have done lately that made them stand out from the crowd. Some of their answers:

• “Someone outlined what he planned to do for the company in his first six months.”
• “I was impressed by a candidate who had prepared an elaborate online portfolio and presentation.”
• “A job seeker brought a performance review from his last employer.”
• “One applicant explained in detail what he knew about our company. I was very impressed with his knowledge and research.”
• “One woman didn’t just recite her skills — she provided many examples of her work.”
• “I liked the way one candidate explained his skills in a way that correlated directly with what we needed for the position.”
• “A candidate gave me a thank-you note right after the interview.”
• “The candidates I recall most are the ones who were persistent in calling to ask whether they got the position.”

Good luck!

Talkback: Have you ever made a personal connection with an interviewer, and do you think it helped you get the job? If you’re a hiring manager, what do candidates do or say that impresses you most (or least)? Leave a comment below.