Popularized by the book "Attached: The New Science of Adult Attachment and How It Can Help You Find — and Keep — Love," attachment style refers to the psychological explanation for how we bond with other humans.

There are three main attachment styles "Attached" authors Dr. Amir Levine and Rachel Heller identify the book:

• Secure people feel comfortable with intimacy and are usually warm and loving.
• Anxious people are often preoccupied with their relationships and tend to worry about their partner's ability to love them back.
• Avoidant people equate intimacy with a loss of independence and constantly try to minimize closeness.

About 40% of people in the U.S. report having a secure attachment style, according to a 2023 poll of 1,000 American adults.

Judy Ho, a forensic neuropsychologist and professor at Pepperdine University, likes to call those people "connected explores."

"They have a generally positive view of themselves and others, and their sense of self isn't overly dependent on what others think of them, what happens in a given day, or what they accomplish," she wrote for CNBC Make It.

If you use these five phrases, you are probably more secure in your relationships than most.

1. 'I can be independent and rely on others, too'

"The securely attached tend to have a strong sense of self, and higher self-esteem, than those who are insecurely attached," Ho says. "They're more likely to have consistently positive feelings about themselves, their abilities, and their perception of acceptance by others."

2. "No."

Harvard-trained psychologist Cortney Warren says emotionally secure people feel comfortable setting boundaries.

"They are clear about what they will and will not do based on their own moral principles, needs and desires," she wrote for CNBC Make It.

3. "I will work on that."

Someone who is self-assured doesn't perceive change as a threat and will make an effort to shift their behavior when necessary.

"They know that taking action is key to personal growth and strengthening connections," Warren says.

4. "I'm sorry you're struggling. How can I help?"

Emotionally secure people understand that if someone is having a bad day, it isn't always a reflection on them.

"Their empathic and non-judgmental nature in relationships makes them great at being supportive," Warren says.

5. "Am I like that?"

An emotionally secure person is able to handle criticism without lashing out.

"If they receive negative feedback, they don't take it personally," Warren says. "Instead, they see it as an opportunity for self-improvement."

If you don't use or identify with these phrases, don't worry, Ho says. Attachment styles aren't static.

"People who believe they can change their attachment styles often do," she says. "While you can't change the past, you can work to build a new, secure attachment."

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