Spencer made the remarks on September 29 during an on-stage conversation with royal biographer Tina Brown at St. Peter’s Chelsea in New York City.

The discussion focused partly on his new memoir, Swan Song: Diana, My Sister, which examines his sister’s life and her experience as a member of the royal family.

During the conversation, Brown asked Spencer whether it was possible for a modern person to remain themselves while living within what she described as the restrictive environment of the monarchy.

Spencer responded that while some people are able to endure life within the institution, others can find it difficult.

He said growing up in a royal family could make the experience easier because a person would become familiar with its particular traditions and way of thinking from an early age.

“If you grow up in a royal family, it’s a lot easier than marrying into it,” Spencer said, according to PEOPLE.

He added that the experience can be particularly difficult for spouses who enter the family from outside the institution, saying that the wives of people who have married into the royal family face a challenging adjustment to a very specific way of life.

Neither Meghan Markle nor Catherine, Princess of Wales, was mentioned by name during the exchange.

However, the comments came amid continuing public interest in the experiences of women who have married into the British royal family.

Spencer's sister, Diana, married then-Prince Charles in 1981. Her marriage and subsequent life as a senior member of the royal family attracted intense media attention before the couple separated in 1992 and divorced in 1996.

Spencer has previously drawn comparisons between the media scrutiny faced by Diana and that experienced by Prince Harry and Meghan.

In an earlier interview with BBC News, he said the treatment of the Duke and Duchess of Sussex in some tabloid coverage echoed what his sister experienced.

He urged people to learn from Diana’s experience, particularly when it comes to the impact of intense media attention on members of the royal family.

Spencer is currently promoting Swan Song: Diana, My Sister, a memoir in which he revisits aspects of his sister's life and death.

The book has attracted attention because of his recollections about conversations involving members of the royal family and his account of events surrounding Diana’s death in 1997.

Buckingham Palace has pushed back on some of Spencer’s recollections.

Following reports about claims in the book, a palace spokesperson said that grief can affect memory, judgment and the way past events are remembered. Spencer has continued to defend his recollections.

His latest comments provide another perspective on the difficulties of becoming part of the British monarchy, particularly for people who enter the institution through marriage rather than being born into it.