"If a friendship lasts longer than 7 years, psychologists say it will last a lifetime."

What kind of psychologist research backs this up?

15 years so far

I had to disagree unfortunately. My BFF and I had been friends for 15 years until I started to move into different life stages. I've settled down and expecting while she is still single. She actually told me she was envious. I tried telling her our different life stages wouldn't change our friendship, but it did. She began pulling away even though I would call and ask her to hang out like we'd always done. I wouldn't bring my SO so it would be girl's night. My actions didn't work though and she just eventually stopped answering her phone. I even stopped by her house a few times and she wouldn't answer the door (I would stop at various times in case she wasn't home). Anyway, I haven't heard from her in about 6 months now. Still fresh wounds I guess. I miss her a lot and our escapades; I always felt we had a great friendship, more like sisters. I still dont fully understand why it ended. =(

I've know my three best friend collective for 45 years. I love them so much, they're scattered over Europe but we come together about once a year. I know for all of my life we'll love each other. I'm going to see 2 of them next weekend in Vienna and I'M SO EXCITED 😍😍

I've known one of my friends for 22 years. We were friends before we could walk. She's cool, but I could survive without her. We don't talk unless she needs something.

Me an my best friend Harold and me and my best friend Hannah we have known each other for almost a 11 years this year (Aug 2015) will be a 11 years :) we all meet the same day in middle school and been friends ever since 

Love my bestie!! We've been friends for 17 years and I don't know what I'd do without her!!

Known this girl for almost 15 years. She is like a sister to me!

Known this girl since sophomore year of high school. She's basically my sister. Love her! 😍

It depends. I have had a lot of friends for like 10 years and then move and never hear from again. I've also got friends who have been in my life since practically forever.