--- description: There's a connection between yawning and your real friends title: 5 Things You Didn’t Know About Friendship, Backed by Research image: https://static.time.com/v3/assets/bltea6093859af6183b/blt17977d9b5334e199/69885a6c35ba6f12d5c0e23b/group-friends-rear-view.jpg?branch=production&width=1080&quality=75&auto=webp&crop=16:9 ---  * [Ideas](/section/ideas/) ## Ideas Update your preferences in [Account Settings](/account/preferences/) Close * [Psychology](/tag/psychology/) ## Psychology Update your preferences in [Account Settings](/account/preferences/) Close # 5 Things You Didn’t Know About Friendship, Backed by Research by [Eric Barker](/author/eric-barker/) ## Eric Barker Update your preferences in [Account Settings](/account/preferences/) Close Jul 14, 2015 4:01 AM CUT  Rear view of friends walking together in field Rear view of friends walking together in fieldGetty Images by [Eric Barker](/author/eric-barker/) ## Eric Barker Update your preferences in [Account Settings](/account/preferences/) Close Jul 14, 2015 4:01 AM CUT Some insights about friendship from research, with links to the studies: * The secret to making friendships last is [staying in touch every two weeks](http://www.bakadesuyo.com/what-keeps-friendships-alive "undefined"). * [Yawning](http://www.bakadesuyo.com/can-yawning-tell-you-who-your-true-friends-ar "undefined") can tell you who your real friends are. * Yes, the enemy of your enemy [is your friend](http://www.bakadesuyo.com/is-the-enemy-of-my-enemy-my-friend "undefined"). * There is [a limit to how many real friends you can have](http://www.bakadesuyo.com/is-there-a-limit-on-how-many-friends-you-can "undefined") — in life and on Facebook. * More time with friends produces the happiness equivalent of an extra [$133,000 a year](http://www.bakadesuyo.com/how-much-is-more-time-with-your-friends-worth "undefined"). For more on the science behind making new friends and strengthening the friendships you have, click [here](http://www.bakadesuyo.com/2013/11/how-to-make-friends-easily/ "undefined"). **Join over 195,000 readers. Get a free weekly update via email** [**here**](http://eepurl.com/o6uAD "undefined")**.** **_This piece originally appeared on_** [**_Barking Up the Wrong Tree_**](http://www.bakadesuyo.com/2012/03/5-things-you-didnt-know-about-friendship/ "undefined")**_._** Related posts: [How To Stop Being Lazy And Get More Done – 5 Expert Tips](http://www.bakadesuyo.com/2014/08/how-to-stop-being-lazy/ "undefined") [How To Get People To Like You: 7 Ways From An FBI Behavior Expert](http://www.bakadesuyo.com/2014/10/how-to-get-people-to-like-you/ "undefined") [New Harvard Research Reveals A Fun Way To Be More Successful](http://www.bakadesuyo.com/2014/09/be-more-successful/ "undefined") ```json [{"@context":"https://schema.org","@type":"OpinionNewsArticle","@id":"https://time.com/3953794/friendship-science-research/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/3953794/friendship-science-research/"},"headline":"5 Things You Didn’t Know About Friendship, Backed by Research","datePublished":"2015-07-14T04:01:42.000Z","dateModified":"2026-03-31T08:35:33.763Z","description":"There's a connection between yawning and your real friends","url":"https://time.com/3953794/friendship-science-research/","keywords":["Psychology","Friendship","Science topic"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt17977d9b5334e199/69885a6c35ba6f12d5c0e23b/group-friends-rear-view.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Eric Barker","jobTitle":null,"url":"https://time.com/author/eric-barker/"}],"articleSection":"Ideas","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt17977d9b5334e199/69885a6c35ba6f12d5c0e23b/group-friends-rear-view.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"group-friends-rear-view","caption":"group-friends-rear-view","creditText":"Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/ideas/","name":"Ideas"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/psychology/","name":"Psychology"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/3953794/friendship-science-research/","name":"5 Things You Didn’t Know About Friendship, Backed by Research"}}]},{"@context":"https://schema.org","@type":"VideoObject","name":"Mannes on the Street: How Do You Split Expenses With Friends?","description":"MONEY VIDEO","thumbnailUrl":"https://cdn.jwplayer.com/v2/media/FO0yRCRK/poster.jpg?width=720","uploadDate":"2014-06-01T04:26:01.000Z","contentUrl":"https://cdn.jwplayer.com/manifests/FO0yRCRK.m3u8","embedUrl":"https://time.com/3953794/friendship-science-research/","duration":"PT1M20S","potentialAction":{"@type":"SeekToAction","target":"https://time.com/3953794/friendship-science-research/?jw_start={seek_to_second_number}","startOffset-input":"required name=seek_to_second_number"}}] ```