One of the most common questions I hear as a friendship coach isn't about making new friends — it's about getting closer with the friends we already have. 

I'm glad people are asking, because the Harvard Study on Adult Development — the longest-running study on happiness — finds that the No. 1 factor that influences our overall health and wellbeing is the quality of our relationships.

What good is a long-term friendship if you secretly feel like you can't be yourself? What's the point of having a large social network if you don't have anyone who knows the real you?

I've been studying the science of connection, cooperation, and conflict for 10 years. And for those who are struggling to deepen their friendships, I always suggest following what I call the "A.D.O.R.E." practices —  five evidence-based ways to develop connection: 

• Appreciation: Say 'thank you'
• Desire: Express platonic longing
• Openness: Be vulnerable
• Reliability: Build trust
• Experiences: Spend time together

Here's how to put them in action: 

Appreciation: Say 'thank you'

You might not feel like you have to say "thank you" to people you're closer to. But stating your gratitude can remove any doubt that you appreciate them, and that affirmation can bring you closer.

What does this look like in action? 

• After sharing a belly laugh with a friend, tell them they are one of the funniest people you know. 
• During dinner, tell a friend how much you enjoy hanging out with them. 
• When a friend tells you about a work accomplishment, tell them how much you admire their ambition.

Highlight and affirm key traits to help your friend feel seen and valued. When all else fails, a simple, "I appreciate you" goes a long way.

Desire: Express platonic longing

We often reserve the word "desire" for romantic contexts, but it's important to demonstrate platonic longing as well. 

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It's tempting to treat friendship as an afterthought — something that you'll get around to when things finally slow down. But this passivity can make friends feel like they don't matter.

Instead, try expressing your desire by:

• Initiating hangouts, which says "I desire your companionship."
• Asking questions about their life, which conveys "I desire to get to know you better."
• Looking for meaningful and proactive ways to show up for them, which lets them know, "I desire to help you."

These gestures can make your friends feel wanted.

Openness: Be vulnerable

The "beautiful mess effect" is a psychological phenomenon in which we find other people's vulnerability attractive while judging our own in a negative light. Vulnerability brings us closer to people we love, but the fear of rejection can keep us from opening up. 

If you want more depth in your friendships, lean into the discomfort. This can look like:

• Sharing an unpopular opinion (at the risk of appearing different).
• Asking for help (at the risk of appearing weak).
• Sharing a "win" you're proud of (at the risk of appearing boastful).

Vulnerability can look different for everyone depending on their specific fears and complexes. But revealing our imperfections is one way to be more fully known and accepted by others.

Reliability: Build trust

Reliability has a powerful ripple effect. When we show new friends that they can count on us, it builds trust, and trust makes people feel safe — a major prerequisite to opening up and going deep. 

So if you're looking to deepen a friendship, find ways to show that you're reliable. For example:

• Offer to help without being asked.
• Show up for plans you committed to.
• Try not to spill confidential information (to or about your friend).

Experiences: Spend time together

It's difficult to get to know someone without spending time together and sharing experiences. In fact, research from the University of Kansas suggests that it takes about 50 hours of socializing to move someone from "acquaintance" to "casual friend," 90 hours to get to "friend," and over 200 hours to get to "close friend." But in today's time-crunched world, that can feel impossible.

For people who are struggling to make time for friends, I suggest two things:

1. Create a weekly or monthly routine. This makes it easier for you to see each other consistently without all the mental labor required to align your schedules over and over again, which can be overwhelming. Perhaps you commit to 30-minute phone calls on Friday mornings or you attend trivia night every first Tuesday of the month. 
2. Redefine what it means to spend time together. If you're still envisioning hangouts as hours-long brunches or nights out, you'll continue to say you don't have time for them. But what if spending time together looks inviting your friend to join you on a grocery trip while they fill you in on their work drama? Or co-working at a local coffee shop so you can chat between emails? Think of ways to layer your daily tasks with friend time instead of trying to scrape up additional hours for connection.

The key takeaway is that spending time together doesn't "just happen" — at least, it doesn't just happen in adulthood. So try to find ways to be intentional about it.

Danielle Bayard Jackson is a women's relational health educator who speaks nationally about the science of women's platonic connections. She is the director of the Women's Relational Health Institute and the author of "Fighting for Our Friendships: The Science and Art of Conflict and Connection in Women's Relationships." Follow her on Instagram at @daniellebayardjackson.

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