The Duke of Sussex has spoken candidly about the effects of “unconscious bias” on racism, warning people must understand how their upbringing and environment causes them to be prejudiced without realising it.

The Duke, writing in the Duchess of Sussex’s guest edited issue of Vogue magazine, put forward an impassioned explanation of how stigma is “handed down from generation to generation”, saying too many people fail to acknowledge their own bias.

Speaking of “unconscious bias”, which he described as “something which so many people don’t understand, why they feel the way they do”, the Duke said: “Despite the fact that if you go up to someone and say ‘what you’ve just said, or the way you’ve behaved, is racist’ - they’ll turn around and say, ‘I’m not a racist’.

“‘I’m not saying you’re a racist, I’m just saying that your unconscious bias is proving that because of the way that you’ve been brought up, the environment you’ve been brought up in, suggests that you have this point of view - unconscious point of view - where naturally you will look at someone in a different way.' And that is the point at which people start to have to understand.”