By VALERIYA SAFRONOVA
Eyes alert, wearing pearls and a necklace with the word “Fearless,” Kelly Williams Brown, the author of the best-selling guide for millennials, “Adulting: How to Become a Grown-up in 468 Easy(ish) Steps,” and, more recently, “Gracious: A Practical Primer on Charm, Tact and Unsinkable Strength,” boarded a downtown No. 6 train in New York. She politely asked a stranger occupying the seat next to an open one: “Excuse me, do you mind if I sit here?”
A few steps behind was her friend Lizzie Post, the great-great-granddaughter of the etiquette expert Emily Post and co-president of the institute she founded in 1946. Dressed simply in a white button-down and jeans, Ms. Post had a cool demeanor that masked her discomfort with subway travel (a Vermont native, she once got very lost underground on her way to the airport). The friends were setting out to assess and discuss the state of modern manners in a variety of settings around the city.
“Can we talk about phone conversations on the subway?” asked Ms. Post, who is an author of the 19th edition of “Emily Post’s Etiquette,” a recently released 722-page volume that covers social networking, tipping, political conversations, invitations, table manners and much, much more. “That’s just annoying. This is a trapped audience.”
The conversation turned to public displays of affection. “Arm around, a leaning in, a quick smooch is fine,” Ms. Post said. “The lingering and the caressing is what people don’t like.”
“Also noises,” Ms. Brown added.
“Make-out noises aren’t O.K. anywhere in public,” Ms. Post said.
“A head on the shoulder? Yes,” Ms. Brown said. “Erotic inner arm rubbing? Probably not. Don’t be moving a lot and you’ll probably be O.K.”
Earlier in the day, at the Metropolitan Museum of Art, the chatter between the two was less racy.
“If I am in a museum by myself, I always carry some headphones with me for those times I want it to be quiet even though it might not be,” Ms. Brown said.
Ms. Post said: “That, to me, is a big part of etiquette. It’s not about changing the world around you and pointing out the mistakes of others; it’s about finding your own way to be centered and at ease.”
Ms. Brown pulled a pouch out of her bag and rummaged through her sunscreen, an eyeglass repair kit, superglue, some chargers, string, miniscissors and an insurance card. “Because I’m a fidgeter, and I know there will be those situations, I carry around this fancy-schmancy organic Silly Putty.”
In a taxi cab en route to WeWork, a co-working space in Midtown Manhattan, Ms. Post and Ms. Brown discussed a feminist etiquette conundrum: men who hold the door. “Nowadays you can’t assume,” Ms. Post said. “It might be a first date, and you don’t know whether it’s a woman who values chivalrous acts or doesn’t. The best thing you can do is ask. And that way it becomes a choice for the woman.”
Seated around a conference room table at WeWork, Ms. Brown and Ms. Post moved on to the subject of business meetings and the ever-present interrupter.
“Standing up for myself while still maintaining a very high level of politeness only further underlines maybe how poor that behavior is,” Ms. Brown said, adding: “‘John, I love your enthusiasm for this. I’m almost finished with what I have to say.’ They might feel chastised, but that’s O.K.”
Ms. Post suggested it might help to speak to a chronic interjector separately. “‘John, I’ve been noticing lately in meetings, as I’m working on a thought or getting us through the agenda you have a lot of comments,’” she said.
If you decide to use email instead of speaking directly to a person, Ms. Post suggests some things to remember to keep your digital communications skills work-appropriate: Email isn’t private, it’s not always reliable and your boss owns it.
Workday over, the two headed to Ruffian Wine Bar and Chef’s Table in the East Village, where it quickly became clear how much they both dislike group dinners. “I don’t do big birthday dinners,” Ms. Brown said, adding that more than six people, including the host, is too many when it comes to choosing dishes or splitting a bill.
She acknowledged that large dinners are a reality, but, she said, “Just because an invitation is issued doesn’t mean you have to accept it.”
“Bingo,” Ms. Post said. “Say, ‘I’m sorry that’s not a good night for me,’ and just leave it at that.”
“If someone pushes,” Ms. Brown said, “I will say, ‘Oh, I’m so sorry, I have plans with my family.’ Because I am my family. And my plans are to watch Netflix instead of going to an expensive group dinner.”
When it comes to one-on-one dinners, both said the villain was usually the phone. “Every time you look at your phone when you’re out with someone else, you’re saying that whatever is happening elsewhere is more important than what’s happening with you right now,” Ms. Brown said.
To get the attention of someone distracted by things like Twitter or Tinder, Ms. Post suggested a direct inquiry, like, “Hey, do you need to be on Instagram right now?”
In her book, Ms. Brown offers some tips on not letting the internet and social media take over your life. She suggests knowing what you need from it every time you sit down, making sure you are willing to stand by whatever you say forever, and not losing any sleep over mean comments.
“Everyone talks about manners as a thing of the past,” Ms. Brown said.
“You and I certainly don’t,” Ms. Post said. “We are on a crusade. Etiquette is alive. It is real. It is living.”