(CNN) -- Chastity Bono, gay-rights activist and child of performer Cher and the late entertainer and politician Sonny Bono, is in the early stages of transitioning from a female to a male and will be known as Chaz, his spokesman said Thursday.

Activist Chastity Bono is transitioning from female to male and will be known as Chaz. more photos »

"Chaz, after many years of consideration, has made the courageous decision to honor his true identity," Howard Bragman said in a written statement.

"He is proud of his decision and grateful for the support and respect that has already been shown by his loved ones. It is Chaz's hope that his choice to transition will open the hearts and minds of the public regarding this issue, just as his 'coming out' did nearly 20 years ago."

Someone's decision to transition does not necessarily mean they are undergoing gender reassignment surgery, and in many cases they do not, said Mara Keisling, executive director of the Washington-based National Center for Transgender Equality.

"The whole media fixation on surgery is kind of misplaced," she said. "Almost no transgender people ever have surgery. We don't have any idea how many do." iReport.com: Do you have a transgender story?

An estimated one-quarter to one-half percent of the American population is transsexual, however, Keisling said. "It's sort of a general term that encompasses both or either a social transition or a medical transition."

Don't Miss Oprah.com: Pain of being born in wrong body

Keisling said she was unaware of the specifics in Bono's case, but speaking generally, a transition means that he will now want to be "known, seen, viewed" as a male.

"The actual details depend on his needs and wants and his doctor's needs and wants," she said.

Bragman asked that the media "respect Chaz's privacy during this long process, as he will not be doing any interviews at this time."

Now 40, Bono as a little girl made regular appearances on her parents' show, "The Sonny and Cher Comedy Hour." As an adult, he has been a longtime gay-rights advocate and been closely associated with the Gay and Lesbian Alliance Against Defamation. See more photos from Chastity Bono's life »

Bono's father, Sonny Bono, was a U.S. representative from California when he was killed in a skiing accident in January 1998.

All About Sonny Bono • Cher