Here's why:
* Accents are learned: Accents are patterns of pronunciation that are learned through exposure to language. Children learn to speak by imitating the people around them, so their accent will be influenced by the way their family, friends, and community speak.
* Regional and social variation: There's a wide range of accents within the UK, influenced by factors like geography, social class, and even age.
* Babies start with a basic "baby talk" sound: Babies all over the world start with a very basic sound system that doesn't yet resemble any specific language or accent.
Therefore, while it seems like British people are "born with accents", it's more accurate to say they develop their accents over time through the process of language acquisition.