This One Cheap Intervention Reduced Rape in Nairobi Slums By 63%


In the slums of Nairobi — places with names like Umoja, Mathare, Karogocho, and Kibera — you’ll find moments of beauty and signs of hope everywhere. The smile of a schoolkid trying to catch a bubble during lunch break (pro tip: kids love bubbles). The teenager who invites you into his home to “check out his crib.” Everyone, everywhere going out of their way to help a lost-looking foreigner be a little less lost.

But you will also find desolation, in the eyes of a man consumed by his consumption of chang’aa (a sometimes-homemade, sometimes-gang-made liquor often spiked with jet fuel and battery acid). Desperation, in the eyes of a child who may not find a meal. Hopelessness in the scope and scale of myriad heartbreaking issues confronting the men, women, and children living there. 

One of these issues is rape. Arguably the darkest statistic about life in the slums of Nairobi is the prevalence of rape: Up to one in four teenage girls are raped each year – sometimes as a result of just going to the latrine.

So, when there’s an astoundingly successful intervention that significantly reduces rape, it’s worth shining a light on it. Such is the case with a recent study out of Stanford University School of Medicine and Lucile Packard Children’s Hospital. It looked at whether teaching young girls a self-defense course would reduce the incidence of rape. It did, by a staggering amount.

Here’s how it worked: The self-defense course, developed by San Francisco-based NGO No Means No Worldwide, included verbal and physical self-defense techniques to prevent rape and sexual assault. It was taught to about 400 high-school-age girls, aged 14-21, in Karogocho and Kariobangi (two Nairobi slums), with another 120 girls serving as a control. The study was non-randomized “to prevent cross-contamination across study groups.” Importantly, the intervention was cheap — just $1.75 per trainee.

The results were staggering: “In the 10 months after receiving self-defense training, more than half of these girls reported using what they had learned to fend off would-be attackers. The proportion of them who were raped fell from 24.6% in the year before training to 9.2% in the 10-month period after… In contrast, among girls who had life-skills classes, the proportion who became victims of rape remained about the same.”

That’s an absolute 15.4% drop, and a relative reduction of 63%.


The researchers noted that rapes perpetrated by the two most common groups, boyfriends and relatives, dropped significantly. Additionally, almost 60% of girls trained in self-defense reported using the skills they learned, and those who were raped were vastly more likely to disclose it — for girls trained in self-defense, from 56% pre-training to 97% post. In other words, the intervention was a resounding success.

Before you get too excited, a word of caution. This study doesn’t say that teaching self-defense techniques anywhere, for any age group, will lead to such a profound reduction in rape. The slums of Nairobi may be a unique case. Perhaps their atrociously high initial rates make reducing the incidence there “easier,” and a host of other factors could also play a role. The external validity of the intervention just hasn’t been shown. It may be less effective in other areas of Kenya, or even other areas of Nairobi. It also wasn’t a randomized controlled trial, which dilutes its usefulness a bit. Overall, we just don’t have enough data to say if this intervention would work elsewhere, and more studies need to be undertaken in different contexts.

But here’s what we can say: An intervention that costs $1.75 per trainee reduced the chance that a Nairobi teenager would be raped by 63%. Add that to the signs of hope column.

This post originally appeared at Project Millennial, a group of Millennials' take on health care and health policy.