Jason Collins, center for the Washington Wizards of the NBA, made waves this week when he announced he was gay in a Sports Illustrated cover story, becoming the first active professional male athlete on a major U.S. sports team to come out publicly as gay.

“I’m a 34-year-old NBA center. I’m black. And I’m gay,” Collins said in the story.

Once the story broke, several public figures voiced their support for Collins. In a press conference Tuesday, President Barack Obama said he talked to Collins Monday and said he, “couldn’t be prouder” of him. Former President Bill Clinton said in a statement Monday, he hoped everyone “extend to him their support and the respect he has earned.”

Many current and former NBA players also publicly announced their support for Collins. Kobe Bryant, shooting guard for the Los Angeles Lakers, stated on Twitter he was proud of Collins, and tweeted, “Don’t suffocate who u r because of the ignorance of others.”

NBA Commissioner David Stern said in a statement: “Jason has been a widely respected player and teammate throughout his career, and we are proud he has assumed the leadership mantle on this very important issue.”

While Collins is the first active male professional athlete to publicly come out as gay, he is not the first active professional athlete to do so — there have been many female professional athletes to have publicly announced they were gay in the past.

For instance, Billie Jean King and Martina Nvratilova, professional female tennis players, came out as gay in 1981. Since then, several other female athletes in tennis, golf, soccer, basketball, etc. have also come out as gay.

More recently, Brittney Griner, No. 1 pick in the 2013 WNBA draft, came out as gay in an interview with Sports Illustrated on April 17, 2013. While Griner and Collins are both professional athletes on major U.S. sports teams, Griner’s announcement received relatively little publicity, while Collins’ announcement has become one of this week’s most-popular stories.

Why have so many female athletes publicly announced they are gay, while so few male athletes have done so? Furthermore, why did Griner’s announcement receive such little publicity compared to Collins’?

The answers to these questions have to do with stereotypes associated with gender and sexuality, not so much with professional sports or its players.

Stereotypical characteristics for females are: weak, bad at sports and subordinate. Male stereotypical characteristics are: strong, good at sports and dominant. However, when a person announces he or she is gay, the traditional characteristics associated with the person’s gender are often reversed, with males being seen as weak and bad at sports and females being viewed as strong and good at sports.

Encouraging more professional athletes to come out as gay is not as simple as changing the culture of professional sports in organizations like the NBA, WNBA, NFL, MLB, etc. To help athletes, and others, feel comfortable in publicly coming out, the stereotypes associated with gender and sexuality must be changed. Society, not just professional athletes, must rid itself of stereotypes associated with gay males and females.

Collins’ announcement is a huge step in the right direction for gay professional athletes, but it is still only one step. Many more steps must be taken, not to change professional sports, but to change mindsets.