Bruce Jenner tells all in revealing interview

Jenner then symbolically takes "the damn ponytail out" and lets his hair flow for the remainder of the interview with Diane Sawyer.

"For all intents and purposes, I am a woman," he said. (The broadcast, however, referred to Jenner with the male pronouns, which was done by request.)

"I've been very confused with my gender identity" since childhood. He used to try on dresses in his mother's and sister's closets.

He told the interviewer his "brain is more female than it is male."

"I'm stuck here in the middle," he said, referencing being a man but not comfortable in his skin. He has felt like a woman the whole time and feels more comfortable identifying as one.

Jenner immediately shot down any contention the interview was a publicity stunt to promote "Keeping Up with the Kardashians" and instead showed conviction about its purpose: "I really firmly believe that we're going to make a difference in the world with what we're doing" by announcing his decision to re-emerge as a woman after being born a man.

The topic of the interview then turned to Jenner's sexual orientation.

"I am, as far as I know, heterosexual" and not gay, he said. Sexuality is "who you're personally attracted to," and gender identity is in the soul and who you identify with inside, he said.

Jenner suggested he ran to win his 1976 Olympics gold medal because fear propelled him to run away from the truth. After the win, Jenner took estrogen hormones for five years in the 1980s. He said he stopped to protect the quality of life of the two children he had before marrying Kris Jenner.

"Those are the only ones I'm concerned with. I can't let myself hurt them," he said about his son and daughter.

Jenner said as he got older, he knew he had to go through with the transition.

"Bruce lives a lie. She is not a lie. I can't do it anymore," he said.

Four of Jenner's six biological children appeared on camera during the broadcast. All of them are supportive of their father's decision.

The two who did not appear on camera, Kendall and Kylie Jenner, said in a statement, "If he's happy, we're happy."

Khloe Kardashian took it the hardest because her relationship with her biological father was cut short and her romance with Lamar Odom ended badly, Bruce Jenner said.

Kim Kardashian came around to the transition after talking about it with her husband, Kanye West. "I can be married to the most beautiful woman in the world, and I am. I can have the most beautiful little daughter in the world, I have that, but I'm nothing if I can't be me," West said.

"Since then, Kimberly has been, by far, the most accepting," Jenner said.

As part of the exclusive interview, Jenner took Sawyer and a camera operator to a "glam room" preview, and pulled out a little black dress from a closet, then cracked a joke: "...and the good news, Diane, you won't be the tallest girl in the room. Isn't that wonderful?"

The Kardashians will appear on "Good Morning America" on Monday to follow up Friday's interview.

The E! Network also announced Jenner's transition will be broadcast in a documentary series debuting on July 26.