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Sophie and Jack were yesterday confirmed New Zealand's most popular baby names of 2008.

Jack has led the boys' list for the past four years, while Sophie moved in to replace the previous year's favourite Ella, now in third place, according to the Births, Deaths and Marriages office of Internal Affairs.

The Internal Affairs list includes a number of the quirky and less-than-popular names as well.

Flight of the Conchords star Jemaine Clement's daughter is named Sophocles Iraia, while other left-of-centre choices included Ardeth (a character from the movie The Mummy), Benaiah, (a Biblical term meaning "God has built"), and Jazyah (a poll-tax historically required of infidels by Muslim conquerors).

Internal Affairs refused to register Fish and Chips, Masport, and Mower, Yeah Detroit, Stallion, Twisty Poi, Keenan Got Lucy, and Sex Fruit.

United States baby name expert Laura Wattenberg - who has studied world trends for 30 years - said Sophie and Jack had a lot in common.

They were familiar, traditional names that had not been common for the past 30 years and they had a fashionable arrangement of consonants and vowel sounds.

Rohanna McCann of Glenfield, Auckland, chose the name Sophie for her second child, born on September 17, 2008, for no other reason than that it rolled off her tongue every time she looked at the unnamed baby.

It was not a name she had lined up before the baby was born: "I didn't even like the name when I was pregnant," Rohanna McCann said.

She was surprised to hear the name was top of the list of popular baby names. Sophie Townsend has an older brother Lukah, 2, and Rohanna McCann does not know any other babies with the same name as her.

Sophie, or Sofie derives from the Greek Sophia, meaning "wisdom", and is popular all over the world, however you spell it, Laura Wattenberg said.

"There is something about the name that speaks to parents all over the world today."

Like many of the others in the list of top 30 names for girls, Sophie was popular in the 1900s.

It also follows the trend of soft vowel sounds Emily was the the most popular name in the United States last year, Olivia was Britain's favourite and Mia was the most popular name for girls in Australia.

Isla made it on to the list of top 30 names in New Zealand this year. Lila is one of the hottest names in the US.

Laura Wattenberg said she would not be surprised to see Ida coming back.

"Parents' names sound boring, grandparents' sound old but our great-grandparents' names start to sound more interesting," Laura Wattenberg said.

Jack dominates the charts in English-speaking countries. It is the top name in Britain and Australia, while in the US Jacob is most popular.

Wattenberg said there was no coincidence that Jack and Jacob were the most popular names. "The 'J' and the 'K' sounds are incredibly popular. It sounds good to us now. Sounds have styles that change just like haircuts and hemlines," she said.

Jack, which is Hebrew and means "God is gracious" was exclusively a nickname for John until this century.

"Jack has a hard crunchy sound. Most boys names now are softer and ending in consonants like 'N' but some parents could be looking for a harder, more boyish sound," Laura Wattenberg said.

She said the high turnover of other boys' names on lists was a relatively new trend as historically popular boys' names would hold their position for years.

But in 2008 New Zealand's list saw Riley jump from number 17 to sixth place on the list, Logan and Joseph were bumped off the list while George and Charlie slipped on.

Vincent dropped off the top 100 altogether and Brooklyn jumped from number 100 to 87.

"We are rushing to find things that are new and fresh so there is a faster turnover than there used to be," Laura Wattenberg said.

Each year some of the popular names were inspired by celebrities but Laura Wattenberg said usually the number one name wasn't.

Girls top 30
Sophie
Olivia
Ella
Isabella
Charlotte
Lily
Emma
Emily
Jessica
Grace
Hannah
Chloe
Ruby
Lucy
Ava
Amelia
Madison
Maia
Mia
Holly
Sophia
Zoe
Paige
Georgia
Kate
Brooke
Maddison
Samantha
Sienna
Isla

Boys top 30
Jack
James
William
Samuel
Joshua
Riley
Liam
Oliver
Benjamin
Daniel
Thomas
Jacob
Ethan
Jayden
Noah
Ryan
Lucas
Luke
Max
Hunter
Matthew
Lachlan
Alexander
Dylan
Connor
Blake
Tyler
Caleb
Charlie
George