In the United States, a woman who publicly speaks out for equal rights for women or states that men should stop harassing and abusing women may be harassed or might even face rape or death threats.

I know this firsthand from advocating for the end to street harassment and most of my feminist activist allies have experienced these extreme responses too. Ridiculously, even advocating for something as seemingly basic as "potty parity" for women, as feminist writer Soraya Chemaly did earlier this year, can result in public ridicule and sexism.

While some Americans like to deflect the severity of the treatment of women here by saying women's lots in life are so much worse elsewhere - and women's lives are bad in many regions of the world - our cultural norms can make it pretty bad for women here. Isn't it telling that advocating for women's rights can be dangerous?

The truth is, women are not as valued or respected as men in American culture, nor are our opinions, and this cultural norm directly contributes to our high rates and acceptance of violence against women. This connection became clear to me during a U.N.-organized conference in Istanbul on ending violence against women, held in early December and attended by representatives from 70 countries.

One meeting objective was to review our progress on ending violence against women since 1995 when 189 countries adopted the Beijing Declaration and Platform for Action - Violence against Women. While 135 laws on domestic violence and rape have passed since then, the rates of violence against women have not changed. For example, at least one in three women worldwide have faced forms of gender-based violence, and that figure is much higher in many countries.

Given the statistics, it is not surprising that conference attendees were in agreement that laws are not enough. Executive Director of UN Women Phumzile Mlambo-Ngcuka as well as many other leaders there emphasized the need to focus on changing cultural norms and changing attitudes.

Notably, in a breakout session, Lara Fergus, the Director of Policy and Evaluation at Our Watch in Australia, said that the organization's recent five-year study on preventing violence against women found that attitudes held by both men and women that women are inferior directly contributes to an increase in violence against women.

That makes sense. If we want to end violence against women in the United States, we must end the treatment of women as inferior, including the devaluing of girls and women.

Sadly, this devaluing starts before birth. A 2011 Gallup Poll showed that twice as many Americans wanted sons over daughters. A new study shows that as more companies are offering paternal leave, there has been a 58 percent increase in fathers using their company's paternal leave policy if their child is a boy. If she was a girl, there was no increase at all in fathers taking time off.

Then women's time and work is valued less than men's, and that starts at a young age, too. Research shows that girls are paid less than boys for their housework and chores. In adulthood, overall on average, women make 79 cents for every dollar a man makes, with women of color making even less. Women face a pay gap in nearly every occupation and it's worse for mothers.

Women's opinions also are valued less and less sought after than men's. One of the ways this plays out is through the low number of women in leadership; few people are encouraging and mentoring women to be leaders. Congress is only 20% female. We've never had a female president. The number of women serving on corporate boards is so dismal that there are more men named John, Robert, William or James than there are women of any name. There is a significant lack of tenured female professors at universities, and a new study this month found that men with mustaches outnumber women as heads of medical departments in the 50 leading medical schools.

A key recommendation across the Istanbul conference was engaging more boys and men in this issue. That is true, we sorely need more boys and men speaking out and taking action. Too few are. We cannot end this without them. And most obviously, we need boys and men to not harass or use force and violence against others.

But the biggest takeaway I had from the global convening was an urgency to look at our cultural norms and see if and how they convey that boys and men are more valuable. Then we need to re-think any harmful cultural norms and change them. The reality is, we will make very little progress toward ending violence against women if we do not value and respect girls as much as we value and respect boys.