Like most little girls, Tia Watson loves going on play dates, playing dress-up and dancing ballet. So what sets the 5-year-old apart from other preschoolers?

She is a member of Mensa, the worldwide organization for people with high intelligence.

Membership is open to those who score in the top 2 percent of the general population on an accepted standardized intelligence test.

"Locally, Tia is certainly the youngest member," said Hugh Beaton, the interim gifted-children coordinator of Mensa Hawaii.

Of the state's more than 200 members, Tia is the youngest of four youths younger than 18; the others are 8, 15 and 16, Beaton said.

"I knew that she was a really bright kid," said Tia's mother, Tammi Watson. "She said her first words at 8 months, and she was speaking in long sentences very, very early."

Watson and her husband, Doug, wanted to gauge the preschooler's level before she starts kindergarten this year. So in January, Tia — then 4 years old — met with a psychologist, who administered an IQ test.

"The results were that she was in the top 2 percentile of her age group," said Tammi Watson, 36, of Kane'ohe. Soon after the Watsons contacted Mensa.

While the designation is exciting for the family, life remains the same for Tia, who continues to do what she enjoys most, including playing the piano, reading, and games like hopscotch.

"She learned to read when she was 22 months old and she hasn't stopped," Tammi Watson said.

Favorite topics include dinosaurs, Egypt and the solar system, among others.

"I like to read Dr. Seuss books, Curious George books and space books," Tia said.

Reach Zenaida Serrano at zserrano@honoluluadvertiser.com.