Tribes are more than a group of people with a shared interest. For many, tribes create tight-knit communities that encourage a sense of belonging — and they’re easier to target online, according to a new study.

Facebook topped the list for creating tribes, according to Jerry Johnson, EVP of strategic planning at Brodeur Partners, which produced the research. He said more than four out of five respondents across all generations — millennials, gen x, and boomers — said relationships and communities formed on Facebook were becoming more important in their lives.

Instagram rated second, though it is only popular among millennials. Less obvious tribe locations among boomers were video game social networks including Raptr and PlayFire.

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“If you’re trying to find community, there’s no better place than Facebook,” Johnson added.

Certain brands also attract certain tribes, whether purposely or not. The research looked at the 10 top brands in seven different sectors. For example, people who supported Kraft were more likely to say they were part of faith-based communities, and Coca-Cola fans were more likely to have friends who shared their fashion tastes.

The study looks at how different generations view their tribes, or communities, and how brands and social networks fit into the tribe structure. It suggests it is easier than ever for PR pros to find and target tribes with campaigns.

Millennials are the most eager to join tribes and join the most tribes, likely because they are the most active generation on social networks. Millennials lean on their tribes for support during tough times.

Boomers are less flexible and will join a tribe to combat isolation and loneliness. Boomers were also the most likely to report anxiety without tribes to support them.

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“We need to expand our definition of segmentation and grouping,” said Johnson. “A lot of companies and brands still organize around standard demographics. If I know your gender, age, geography, or profession, I can find you. We need to include in our lexicon and how we communicate this notion of shared interests and shared experiences in tribes.”

Using social media, all it takes is the right influencer or hash tag to get seen by thousands of dedicated foodies, for example.

“Brands should understand the communities and affinity groups they attract and think about how they organize their marketing and communications to reinforce existing ties,” Johnson said. “They could even look at competitors to see if there are gaps the brand can use.”

This story first appeared in PRWeek.