Ask teachers what they gained out on the picket lines, and some will mention their new contract. But many will also say something like this: “The staff feels closer, which helps the school community,” says Jen McSurley, a first-year teacher at Galileo Scholastic Academy magnet school in Little Italy.

Veteran teacher Terri Kopec chimes in: “It helps the students, helps the parents—we feel it, we really do,” she says.

The feeling that teachers got to know each other, got to bond, was a topic of conversation on picket lines from Howard Street to the 100s. Teachers from third-floor classrooms talked to colleagues on the first floor. Eighth grade teachers hung around with the kindergarten set. They baked for each other and barbecued in school parking lots. Teachers spent time with each other in a way they don’t usually have a chance to. 

And many say that’s exactly what they needed.

“I didn’t expect all of this camaraderie,” said first grade teacher Joanna Dobrowolski on the last day of the strike. She’s taught at Galileo eight years. “I didn’t’t really know what a strike was going to be because I’ve never gone on a strike. And so it was interesting to see all of us bond and come together and talk about issues.”

Teachers took up issues they were striking over, but also issues like how best to handle particular students. They shared tips on lesson plans, grading, how to teach reading. It might seem a little nerdy, but teachers like Dobrowolski seemed thrilled to be talking with colleagues about work.

“I’ve gotta steal your book from you!” she told one of her fellow teachers. “They have this great conference sheet on how to conference with kids individually.  So I’m gonna make a copy of that so I have that for my conference sheets. And I even said, ‘I want to come in your room and see how you run that.’ Even though it’s a third grade room, I’m first grade, I can still benefit.”

It wasn’t just in elementary schools where teachers were forging closer ties to one another.

“It was like camp,” said Melissa Barton, who teaches English at Solorio High School on the Southwest Side. “It really felt that way. Or like a retreat, like a professional retreat.”

Lots of teachers at Solorio are convinced the camaraderie they developed during the strike will be good for their school, an unexpected silver lining of the strike.

“I totally think this is gonna help kids,” said teacher Jacob Caplan, one of nearly two dozen new teachers at Solorio this year. That’s a lot of teachers to bring on board at once. The school’s administration had already been working on team building before the strike. There were things like relay races—and teachers were also given an article to read about “social capital,” the idea that teacher collaboration is key to improving schools.

University of Chicago researchers have found that teacher collaboration is one of the most important ingredients in high functioning schools.

On the picket lines, Caplan says teachers began to really feel what social capital is.

“And now I actually see it occurring, that teachers more and more are talking about what kids they have, they’re talking about what works with certain groups of kids.

“I was able to collaborate with English teachers,” said Caplan, a history teacher.  “‘You’re gonna teach re-telling next week? Let’s teach it together.’ So that in history class and in English class they’re getting the same type of vocabulary at the same time.”

Carrie Leana authored the article that Solorio teachers read on social capital. Leana is a business professor at the University of Pittsburgh who’s studied school staffing. She’s surveyed thousands of teachers and reviewed tens of thousands of student test scores.

“The more that teachers talk to one another about what they do, about their work, and the closer they feel to one another, the higher the student achievement gains. So what you see is a direct effect of social capital on student achievement.”

Leana says nationwide, schools are focused on human capital right now, emphasizing individual teacher effectiveness. Leana says schools should pay attention to social capital too—and make sure teachers have time to talk to one another about their work.

Leana says teachers tend to go to each other for advice—not to their principals. That’s why increasing trust among them is so important—it’s the main way teachers get better. Leana says especially in a climate where teachers feel under attack, they will only go to people they deeply trust.

The newfound closeness among Chicago teachers gives researchers like Leana some homework: they’ll have to figure out whether Chicago sees a “strike effect” bump in its test scores this year.