AceShowbiz - Julianne Moore changed her nationality to honour her "foreign mother."

The "Spirit Untamed" star decided to take up British citizenship in 2011 to honour her Scottish-born mother Anne Love Smith as she has always grown up with a "strong identity of being part Scottish."

Speaking about her heritage, she said, "There are a lot of us in America who are first-generation Americans, and I've noticed that a lot of us talk a lot about assimilation - about people coming here and immediately becoming American. But that was not my experience."

"My mother used to tell me all the time that we were not 100 per cent American. My grandparents were very Scottish. My siblings and I all had kilts and we grew up with a very strong identity of being part Scottish."

Julianne penned a book about identity called "My Mom Is a Foreigner but Not to Me", which she based on her own memories and experiences of her heritage.

She added, "I wanted to write this book as a tribute to my mother and to all the other foreign mothers, as well as to the kids growing up in a situation where the person who seems very foreign to the rest of the world is the most familiar person in the world to them."

"I can always recognise someone who is first-generation American by the little things they do. For instance, when my daughter was little, I fixed her hair in two braids because that's how my own mother did my hair. But when she went to school there was only one other girl in her class who wore her hair that way, and that little girl's mother was from Spain - but for fully American little girls, their mothers didn't do that."