Jonathan Berry's life-long dream was to become a military officer, the "tough, rugged, dependable guy that everyone looked up to."

But being a U.S. Marine, surrounded by people who "weren't afraid to step on others to get ahead" wasn't the right fit. After enduring eight weeks of rigorous training, sleep deprivation and "mindless yelling," Berry and 50 others were cut from the program.

Now, he finds happiness and camaraderie in a world about as far removed from the tough-guy Marine culture as anything could be: He's a Brony.

Story continues below advertisement

Bronies are fans – mostly male teens and young adults – of My Little Pony: Friendship is Magic, a 2010 spinoff of the 1980s cartoon originally aimed at young girls.

"I've always enjoyed the virtues of friendship, laughter, honesty, generosity and kindness – these being the core elements to MLP," Berry said while standing in line to register at the BronyCon convention in Baltimore, Md. "It really hit home because it reminds me of the world I would like to live in and the people I would like to surround myself with."

The convention was busy – 10,011 male and female bronies had registered, the vast majority in costume – literally galloping to and from seminars and events that included dress up, role play, meeting the MLP voice actors, workshops on assertiveness and panels on anti-bullying.

On the way to the "Mane Hall," a Brony (rhymes with pony) was DJing a small dance party. Men in their 20s were dancing with abandon.

Berry was wearing an understated Brony T-shirt, in contrast to the majority of attendees robed in full pony costume. This was Berry's first BronyCon and he looked forward to meeting like-minded people, exploring seminars and cosplay, a popular term for dressing up and pretending to be a cartoon character. "I like seeing people getting along despite their differences. [The TV series] really hit home with what I hope to see in real people."

Many might think that adults who enjoy watching children's cartoons or taking part in cosplay are either strange or simply trying to recapture their lost youth.

A 2014 documentary called A Brony Tale, directed by Canadian Brent Hodge, went deeper into the fan culture, exploring valuable aspects of this community. The documentary interviewed a U.S. Army veteran who claims the show helped him cope upon his return from his deployment in Iraq.

Story continues below advertisement

And there is a scientific evidence that cosplay and Brony culture are beneficial to mental health.

Sociologist Jonathon S. Epstein studies youth culture. In his study on LARP (live action role playing), he found there are often feelings of tension and loneliness when some people transform from youths to adults – a feeling of alienation from one's surroundings, or worse, a feeling of not belonging anywhere. Being part of one of these groups provides a counterweight.

In 2011, four psychology researchers studied Brony culture and analyzed how participants lives changed once they joined the group. Their findings show a Brony's behaviour toward others improved, and they were able to interact better socially.

After he left the Marines, Berry started working as a manager at Great Wolf Lodge water park. He first heard about the cartoon from his boss, who was explaining his young daughter's fascination with the show. "It started with my boss showing me images and trying to name off all the ponies, and then I started [watching] clips. Then I was hooked," Berry says.

Many interviewed at the Baltimore BronyCon said their involvement has made them more self-assured and expressive and less anti-social, and has led to career changes.

"Before I became a Brony I was a lot less social than I am now, I think I've become a totally different person," Riley, 20, who did not provide his last name, said. "I hated myself for loving [the show] at the beginning, but I eventually learned to accept it. I met the guys [I'm here with] over the Internet and we've stayed friends for years. We come to the con every year to see each other."

Story continues below advertisement

Clinical psychologist Patrick Edwards, who worked on the 2011 Brony study, says this is a common reaction.

"One parent came up to me two cons [conventions] ago and told me becoming a Brony is what saved her son's life. He was being bullied, was suicidal and was not doing well in school. Then, he discovered My Little Pony: Friendship is Magic and the Bronies. One year later, he has friends and is doing well in school – it really speaks to the power of friendship that can be created by engaging in this or similar groups," he said.

With the exception of Halloween and masquerade parties, cosplay is not popular in Western culture. Even those who participate in historical re-enactments are sometimes derided.

In contrast, other countries have embraced it, particularly with the spread of the Otaku culture, a somewhat subversive adult play practice around anime and manga characters trading, which attracts Japanese and Western people of all ages.

Mizuko Ito is a Japanese cultural anthropologist who works at the University of California, Irvine as an in-residence professor. She sees adult interest in children's media as "a site of resistance to adult values," as she she wrote in her paper, Intertextual Enterprises: Writing Alternative Places and Meanings in the Media Mixed Networks of Yugioh.

"It becomes a receptacle for our dissatisfaction about rationalized labour, educational achievement, stabilized economic value and mainstream-status hierarchies.

Story continues below advertisement

"For adults, these images of childhood are a colourful escape from the dulling rhythms of salaried work and household labour."

Edwards, however, is a little more charitable toward the cartoon fascination. "It teaches them to feel and act differently. We learn the most important messages in life from people who don't actually exist."