"She began to explain to me what cultural appropriation was, the history and heartbreak over how when Black girls do it they’re mocked and judged, but when white girls do it, it's only then perceived as cool," Pugh wrote.
"It was true," Pugh added. "I could see how Black culture was being so obviously exploited."
The actress admitted that she was "defensive" with her friend at the time, but now realises this was her "white fragility coming out plain and simple".
Later in her post, Pugh recalled being taught by an Indian woman about the cultural tradition of using henna for body art, or mehndi as it's known on the Indian subcontinent, which dates back thousands of years in South Asia, the Middle East and North Africa.
Pugh admitted that she thought this meant she couldn't be guilty of cultural appropriation when she wore henna, but later realised she was wrong and hadn't fully respected the woman's heritage.
"I wore this culture on my terms only, to parties, at dinner," she wrote. "I too was disrespecting the beauty of the religion that had been taught to me those years ago."
Pugh, 24, also apologised for appropriating Rastafarian culture in an old Instagram photo, which a fan has recently called her out for.
She wrote: “I was reminded of a photo when I was 17. I braided my hair and painted a beanie with the Jamaican flag colours and went to a friend’s house; proud of my Rastafarian creation. I then posted about it the next day with a caption that paraphrased the lyrics to Shaggy’s song ‘Bombastic’."
"I am ashamed of so many things in those few sentences," she added. “Growing up as white and privileged allowed me to get that far and not know."
Pugh also acknowledged that "stupid doesn't even cut it" when it comes to her mistakes, admitting: "I was uneducated. I was unread."
Pugh ended her post by re-iterating her apology for her past cultural appropriation.
"I cannot dismiss the I actions I bought into years ago," she wrote, "but I believe that we who were blind to such things must acknowledge them and recognise them as our faults, our ignorance and our white privilege and I apologise profusely that it took this long.”