Danny Meyer opened his first restaurant, the Union Square Cafe, at the age of 27. Meyer knew that for the neighborhood restaurant to succeed, it had to have great food. But plenty of restaurants in New York had great food.

Meyer knew he needed more. He wanted to make customers feel great. 

So he encouraged staff to take notes on customers, to remember things like a favorite table or dish. He welcomed criticism from customers and reviewers, so he could learn from it. And he wanted employees with high emotional intelligence, people who had the ability to recognize that a customer needed something fixed.

Fast-forward to today. Meyer has built an award-winning restaurant empire, led by none other than Shake Shack–the ├╝ber-popular fast-casual burger restaurant that quickly grew from a single stand in Madison Square Park to more than 240 restaurants across the world.

Along the way, Meyer identified six emotional skills that he looks for in new hires. Meyer refers to those who possess these six skills as having a high “HQ,” or “hospitality quotient.”

“I don’t know how to teach any of them,” Meyer told Tony Robbins in an interview at Robbins’s recent Business Mastery event. “What we can do is we can teach people on our team how to interview for those emotional skills. And we can also teach our leaders how to celebrate those emotional skills.” Watch the entire interview on Facebook.

Here are the six traits of a high “HQ,” as identified by Meyer:

1. Kindness and optimism

“Skeptics and cynics don’t tend to really care that much about how they make people feel,” says Meyer. “You’re probably someone who is happier yourself when you make someone else feel better.”

Of course, just about everyone is happier when they make others feel better. The key is to find those who know this simple truth.

2. Intellectual curiosity

Too many people today want others to consider them an expert. But Meyer encourages looking for those people who have an unquenchable thirst for learning, because these persons will continue to grow.

In other words, avoid the “know-it-alls” and look for the “learn-it-alls.”

3. Work ethic

For Meyer, work ethic is about more than just working hard; it includes the “excellence reflex.”

“The excellence reflex is a natural reaction to fix something that isn’t right, or to improve something that could be better,” writes Meyer in his book Setting the Table. “The excellence reflex is rooted in instinct and upbringing, and then constantly honed through awareness, caring, and practice.”

4. Empathy

It takes time and effort to understand the how and why behind others’ feelings. And, frankly, most aren’t willing to invest those resources for strangers.

But those who do are able to create wonderful connections with others.

As Meyer puts it:

“In the end, what’s most meaningful is creating positive, uplifting outcomes for human experiences and human relationships. Business, like life, is all about how you make people feel. It’s that simple, and it’s that hard.” 

5. Self-awareness

Meyer compares self-awareness to knowing what your own personal weather report is, on any given day.

“Because hospitality is a team sport,” says Meyer. “And you will infect your team, one way or the other.”

6. Integrity

Meyer defines integrity as “having the judgment to do the right thing, even when it may not be in your own self-interest.”

We can’t undervalue this last one enough, because a person could use emotionally intelligent skills like these both to help or to harm, and there’s often a fine line separating the two. But when you have integrity, not only will you build connection and influence with others–you’ll also do so in a way you can be proud of.

Enjoy this post? Check out my book, EQ Applied, which uses fascinating research and compelling stories to illustrate what emotional intelligence looks like in everyday life.

A version of this article originally appeared on Inc.com.