Amy Alkon (aka The Advice Goddess) writes a nationally syndicated advice column and is the author of a new book on manners with a title we can't print. The book has a chapter called "Eating, Drinking, Socializing," with some interesting advice on food-related manners. I spoke with Alkon by phone about the dynamics of three important food-related relationships: Those between restaurant server and customer, host and guest at a dinner party, and two people on a date, wherever that may be.

AT THE RESTAURANT

Ari LeVaux: Let’s talk about tipping.

Amy Alkon: People believe that they tip solely based on the quality of the server or the service. And the truth is that some people do, but a whole lot just believe they do. We like to believe that we're rational and do things for good reasons. But because our brains like to conserve energy where they can, we have a lot of cognitive biases that lead us to act automatically, in ways that aren't wholly rational.

For example: If you’re male, you’re likely to tip bigger if your waitress is blonde, or if she’s wearing red lipstick, a red dress or a flower in her hair, according to research by French behavioral scientist Nicolas Gueguen.

Other customers will leave bigger tips if the server does things to create the feeling of a familiar relationship between server and customer, like if the server squats down at the table, coming to the customer’s eye level and making conversation seem more intimate. This, in research by Cornell University’s Michael Lynn and colleagues, increased the tip amount by 20 percent for a waiter and 25 percent for a waitress. Giving chocolates or mints with the check also increases the tip. So all of these people who think “I’m fair, I’m rational, I just tip according to the service,” the truth is probably “eh, not so much.”

What if the service is truly terrible?

If you don’t tip at all, it makes you look bad if you’re with dining companions, and the server can pretend that it’s on you, that you were the terrible one. So if the service is egregiously bad, use an idea I borrowed from my pal Steve Dublanica, author of “Keep The Change,” and give your tip to the busboy instead. This means you haven’t cheaped out, but you haven’t also gone all Stockholm Syndrome and rewarded someone for treating you terribly.

But before you take such drastic measures, Alkon warned, make sure you’re positive that the waiter is intentionally slacking off.

Approaching the situation with compassion is counterintuitive but very helpful. Look for clues as to why you’re getting bad service. Is this person having a bad day? Are they covering three sections? Or are they just a person who thinks ‘ha ha, you’re going to wait for your lunch’? Even if you end up giving someone more of a benefit of the doubt than they deserve, you’ll feel better if you call up compassion and say, ‘ok, maybe this person isn’t trying to screw me over. Maybe there’s something wrong.’ And by the way, don’t blame the waiter if the kitchen doesn’t make food you like. Don’t find ways to be cheap.

AT A DINNER PARTY

What do you do if a friend serves you something that’s absolutely disgusting and you don’t want to eat it, or it conflicts with your dietary regimen?

This is America, most of us are getting regular meals. So if you have one meal that’s kind of a bummer, you’ll survive. It’s better not to make the host feel bad, make some kind of scene at the table. Just push the food around on your plate, and hit the Burger King drive-thru on the way home.

That said, here’s gonna be something on your plate that you can eat. And I say this as someone who eats a low-carb, high-fat diet who has been handed a pasta entrée from time to time. Also, considerate host will ask their guests if there is anything they don’t eat. And if you have any major food issues (like things you’re deathly allergic to) you should tactfully let them know upon RSVPing, but also let them know that you don’t expect them to create a whole different meal for you.

So no direct, honest communication about how you really feel?

No. No, no, no. People have this mistaken idea that honesty is the best policy. And it is, except when lying your ass off is a better policy. For example, it does not help the host in that moment to learn that you think they are, a terrible cook. It’s also not your job to tell them. As somebody who gives advice for a living, I have to say, it is really rude to give unsolicited advice. Besides, criticizing people does not make them want to change. It makes them hate you, or want to clobber you, or both.

ON A DATE

What if you’re on a date and he or she cooks you something inedible?

Just make something up that preserves their feelings: “Forgive me, I’m not that hungry,” or “I had a late lunch.” The point is making them feel good in the moment, and then, if you continue seeing them, covertly trying to find a way to improve their cooking, like taking cooking classes together.

What about if your date is doing something weird at the table?

I had a question from a reader, a woman whose date was licking his fingers repeatedly — all of his fingers — at a sushi restaurant. It’s really incredible that people can reach adulthood and not understand that you don’t lick your fingers at the dinner table.

I base the advice I give in my book about what behaviors are and aren’t acceptable at the dinner table on research on disgust by evolutionary psychologists Joshua Tybur and Debra Lieberman. Disgust seems to have evolved to help us avoid disease-causing microorganisms. It’s basically a psychological keep-out sign that pops up when we encounter substance that can infect us like poo, bodily fluids, spoiled food, decomposing bodies. If you think about how pathogens are spread from person to person, one big way is that something is airborne. So, my rule goes like so: If something you’re doing at the table could cause some speck of something to be airborne, it’s bathroom behavior. Nose blowing, finger licking, ear digging, eyebrow plucking, removing your fake eye, all are no-gos. Get thee to the restroom.