CHICAGO — Most of the two dozen former pimps and madams questioned by DePaul University researchers for a study on Chicago’s sex trade had suffered both physical and sexual abuse as children.

The study, “From Victims to Victimizers: Interviews with 25 ex-pimps in Chicago,” by researcher Jody Raphael and Brenda Myers-Powell, found 88 percent of those surveyed suffered physical abuse growing up, while 76 percent endured sexual abuse. In many cases, the abuse forced them to leave home early and turn to pimping to survive.

The majority also traded sex for money before becoming pimps, Raphael said. Of the 25 former pimps interviewed, seven were women, nearly all of whom had been victims of violence and prostitution.

Myers-Powell, who spent more than 20 years as a prostitute, works as peer coordinator for Cook County Sheriff Tom Dart’s prostitution intervention team and does advocacy work through the Dream Catcher Foundation, which helps victims of prostitution. For the study, she spent about two hours interviewing each former pimp. Each was paid $250.