It’s a debate that will be familiar with many millenial friendship groups – and has no doubt dominated plenty of recent conversations.

Just what is it about Taylor Swift that makes her so stratospherically popular?

Not only has her music garnered more than 26 billion streams on Spotify and helped to attract more than 281 million to her Instagram page, she’s also engaged a brand new audience as the girlfriend of Kansas City Chiefs tight end Travis Kelce.

Meanwhile, millions more tuned in to last night’s Superbowl game to watch her in the VIP box, cheering on her boyfriend.

Now, experts have revealed the intriguing, science-based reasons why Swift is such a global phenomenon – and it’s got little to do with her true personality.

One of the major factors, experts say, is simple familiarity. The more Taylor and her music surround our daily lives, the more we grow to like her.

This is a psychological phenomemon known as the ‘mere exposure effect’ – studies involving repeated television commercials have found viewers grow to prefer the products they see on screen most often.

A study published in PLOS One had participants undergo imaging tests to see which types of music activated the brain’s reward system.

The researchers found that people who listened to music they were familiar with were more likely to have the pleasure centers in their brains light up than those who listened to music that they said they liked.

‘Familiarity seems to be a crucial factor in making the listeners emotionally engaged with music,’ the team wrote.

Another reason for the 34 year-old’s popularity is that her songs are uniquely catchy. And scientists have dissected what makes an earworm.

A 2017 study from the American Psychological Association, for example, found that catchy songs include ‘melodic turning points’ between different sections of the song like the verse, chorus, and bridge.

Researchers note that, in Taylor’s case, she often uses one-note melodies in certain sections of her songs that slowly build up.

Dr Cynthia Gordon, an associate professor of linguistics at Georgetown University, said in a university blog post that Taylor’s longevity – starting with her 2007 debut album – makes her a hit.

‘She’s young, but she’s had quite a long career, so her words have been out there,’ she said.

‘We also have music videos and social media that have spread her music. These lyrics have been everywhere, and they’re persistent.’

Dr Gordon also called Taylor ‘a particularly gifted lyricist,’ which makes fans pay more attention to what she’s saying and spend time dissecting their meaning.

‘She likes to drop Easter eggs into her songs with meanings that only her real fans can identify and uncover,’ she said. ‘So I think the role of language in her work is really highlighted, and that has made people pay especially close attention.’

Dr Melissa A Fabello, a relationship coach in California, previously DailyMail.com that it’s ‘not surprising’ that fans feel validated by Taylor’s music, particularly because she allows her lyrics to be vulnerable.

‘What Taylor Swift is fantastic at is creating a narrative world – one that explores many aspects of the human experience, including fears of both abandonment and enmeshment,’ she said.

Enmeshment is when couples, friends, or family members have no emotional independence, meaning they feel like they have to be together at all times or that they have no autonomy.

However, not all of her songs require an ear for detail. Dr Gordon also pointed to Taylor’s hit ‘Shake It Off,’ where she hits back at haters and ‘shakes’ off negative criticism.

‘For me, it’s a song that’s fun. It’s a song that’s catchy, and it also reveals to many of her fans that Taylor Swift can take a joke,’ she said.

‘She’s able to not take herself seriously. She can be humorous, and she can be goofy. And I think a lot of people, myself included, appreciate that.’

Dr Alexandra Gold, a licensed clinical psychologist at Harvard Medical School, told the Harvard Gazette: ‘In the case of Taylor, there’s a couple of things going on. The first piece is relatability.

‘Even though there’s aspects of her that maybe don’t feel very relatable – she’s a celebrity and lives a very different life from her fans – what she is singing about, the lyrical content as well as the emotions that underlie the lyrical content, are very relatable to a lot of people.’

‘There’s something that is very common to the human experience.’

Dr Gold said that this sense of connection is especially strong among millennials and Gen Z, who witnessed Taylor’s rise to fame and grew up alongside her.

‘When they were having some of these first experiences, maybe with relationships or entering adulthood, she was doing that at the same time and singing about that,’ she said.

‘Her life story mapped onto their life story, in some way.’

Additionally, Dr Gold noted that Taylor is so popular because she’s a role model. ‘She is a great example of someone who sticks to their values and shows their fan base that they can reach their goals, whatever those might be,’ she said.

She pointed to Taylor re-releasing her albums in an effort to get the rights to her music back and have more control over her wealth.

‘Seeing someone do something like that could be inspiring for a lot of young people,’ Dr Gold said.