During the the series’ run, pop psychologists have “prattled” about the cultural impact of Friends, with the producers laughing, “It’s only a TV show.”

Aniston’s hairstyle was nicknamed “The Rachel”, and copied around the world. Joey’s catchphrase, “How you doin’?”, has become a popular part of Western English slang, often used as a pick-up line or when greeting friends.

The series has also impacted on the English language, according to a study by a linguistics professor at the University of Toronto. The professor found that the characters used so as an adjective more often than other intensifiers, such as very and really.

The professor believed that although the preference had already made its way into the American vernacular, usage on the series may have accelerate the change. Following the 9/11 terrorist attacks in the United States, ratings increased 17% over the previous season as viewers tuned in for comfort.

The Central Perk coffee house, one of the principal settings of the series, has inspired various imitations worldwide. In 2006, Iranian businessman Mojtaba Asadian started a Central Perk franchise, registering the name in 32 countries. The decor of the coffee houses are inspired by the one in Friends, featuring replica couches, counters, neon signage and bricks.

The coffee houses also contain paintings of the various characters from the series, and televisions playing Friends’ episodes. James Michael Tyler, who plays the Central Perk waiter in the series, Gunther, attended the grand opening of the Dubai cafe, where he worked as a waiter.

 As part of a museum exhibit at Warner Bros. Studios, Central Perk was rebuilt and shown on The Ellen DeGeneres Show in October 2008. Lisa Kudrow revisited the set for the first time after the series finale in 2004