From Nick Frost and Simon Pegg to Ryan Reynolds and Hugh Jackman, a solid bromance is often the foundation for enduring success.
But it's not just celebs who benefit from a buddy, as scientists have found that bottlenose dolphins who build better social bonds go on to father more offspring.
Researchers from the University of Bristol andUniversity of Western Australia studied young male dolphins in Australia's Shark Bay over a 32-year period.
They discovered that dolphins may be using play to develop the social networks and skills they need to be successful later in life.
Lead author Dr Kathryn Holmes of the University of Western Australia told MailOnline: 'Links between play and reproductive success in wild animal populations are exceptionally rare, so we are very excited to have evidence for this in dolphins.'
Researchers have found that dolphins that build better bromances as juveniles go on to be more reproductively successful as adults
Just like celebrity bromances likeRyan Reynolds (left) and Hugh Jackman (right) a good friendship among dolphins can be the basis of cooperation that can last for years
About two decades ago, scientists noticed that the games played by young dolphins bore a remarkable similarity to the mating behaviour of adults.
As adults, alliances of males will 'herd' a lone female away from others and defend her against the advances of other males.
However, researchers also spotted that groups of males and females were observed seemingly taking turns to play the role of male and female adult dolphins.
Dr Holmes explains: 'As in adult mating, the males contact the females' genital slit with their beaks or genitals.'
The resemblance between the behaviour was so striking that researchers proposed it could be a form of practice for adult social behaviour.
As they played, both male and female dolphins would take on both roles, suggesting that this could be an opportunity for both sexes to learn important behaviour.
Much like the celebrity bromance between Nick Frost (right) and Simon Pegg (left) dolphins form their friendships while young and go on to collaborate throughout their whole lives
Additionally, the young dolphins also seemed to be practising a 'come hither' vocalisation called 'pops' which adult males use to keep females close to them.
Young males were much more likely to use these vocalisations if a female was present in the group.
Dr Holmes adds: 'Juvenile male pops are more erratic in their structure than adult male pops, which have a regular rhythm, suggesting that they need practice to achieve the adult rhythm.'
Although there was a clear similarity between the juvenile and adult behaviour, proving that there was a beneficial link between the two proved challenging.
'Males in our study population live well into their 40s and undergo a juvenile period lasting up to 10 years, so you need decades of data on individual males to study the long-term benefits of juvenile play,' says Dr King.
Researchers observed that young dolphins engaged in behaviour (pictured) which was remarkably similar to adult mating behaviour in which males 'herd' a lone female away from rivals
But by analysing genetic and behavioural data recorded over 32 years, the researchers have now found that juvenile play is a significant predictor of reproductive success.
They found that dolphins who developed stronger bonds and spent more time playing in the 'male' roles had more offspring as adults.
This suggests that play might be critical to developing the skills and bonds needed for dolphins to be successful later in life.
One reason that play might be so important is due to the complex levels of coordination required for mating.
Dr Holmes says: 'Adult male dolphins form lifelong friendships, where they repeatedly cooperate in alliances to find mates and compete for them against rival alliances.'
To make matters more complex, these small groups are themselves part of larger 'second-order' alliances of up to 14 males which work together to steal mates and defend against rivals.
Male and female dolphins appeared to be taking turns to play the 'male' or 'female' roles, suggesting that they could be practising important reproductive skills
Male dolphins form lifelong friendships and work together to secure mates for each other, the researchers found that by playing more as juveniles the dolphins could practice their cooperation more and would have more success as adults
These alliances are so key to dolphins' interactions that they are considered the core unit of dolphin social organisation but they are also extremely unusual.
Dr Holmes says: 'The lifelong friendships and alliances of adult males at our study site are uncommon for mammals, because the males are cooperating to access a critical resource that they cannot share.
'We found that juvenile males with strong bonds, who are likely to form an alliance as adults, were more likely to synchronize their play behaviour, suggesting that they practice this skill with their future allies.'
If true, that revelation might help to explain why young animals across so many different species all display some type of play behaviour.
Senior author Dr Stephanie King, of the University of Bristol, says: 'Play behaviour is widespread in humans and other animals, but the reasons that animals play together have long remained a mystery.
'This study provides compelling support for the idea that animals in the wild play together to practice behaviours that will be important for them as adults, and that if they practice enough, they will be more successful as adults.'
