And 700 of his 1,300 subjects grew up in the City of Brotherly Love.
To reach that conclusion, Piquero and his team interviewed those subjects over seven years. He encountered them through the juvenile-court system, focusing on offenders between 8 and 16 years old who had committed felonies that included aggravated assault, robbery and burglary.
Periodically, the team would check in on those kids, even as they moved to Delaware, New Jersey and even Florida.
But in the beginning, all Piquero asked them for was a number.
"I'd say, 'Tell me how many years you think you'll live?' " he said. "And that's all we needed to figure out how much they'd commit to their lives."
The group found that kids who gave high numbers were less likely to become repeat offenders, while their peers with more bleak outlooks were more likely to make return visits to the courtroom.
"Kids who see life only in the short term live in the here and now, don't see the consequences of their actions," he said. "If you say, 'I'll live to be 70,' you see yourself down that road; kids who think they'll die in a few years are just trying to get through the day, or next week of their lives."
Piquero's interviewees blamed the "chaos and disorder" in their neighborhoods for their attitudes: rampant drug sales, shootings and overall blight.
"They can't focus on planning for the future, on making their lives better," he said, "because they're trying to just sort through that chaos."
By the time the study had concluded and the researchers were beginning to compile their data, 45 of the subjects had died of "non-natural causes" - victims of violence, suicide or other tragedies.
Archye Leacock, executive director of the Institute for the Development of African-American Youth, says he sees the same fatalistic attitude daily through his work with the city's youth.
"These kids feel the system controls everything, that they have no say in how their lives are run," he said. "When they go through the courts, they already resent authority. They see themselves as being labeled as criminals, even if it's their first arrest."
Leacock works with juvenile offenders through court-ordered programs, helping them bring structure to their lives.
"When you've been living without rules since you were 4 or 5, and then suddenly you're 13 and you have a man enforcing a curfew on you, you're going to push back," he said.
"But most learn to accept it. They see their friends getting locked up or killed and realize that our method works, that we have their best interests at heart."
Leacock said that once these kids understand that they can have a future, they change their tune.
And that's exactly what Piquero hopes his study will underscore.
"Some of these kids have never been told that they can succeed in school, that they can find employment options," he said.
"If we can reinforce positivity in their lives, we can save them."
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