The New York Times reports today that a former Success Academy teacher videotaped another teacher demeaning and belittling a first-grade student who could not come up with the right response to her question. Other former SA teachers confirmed that children were subject to psychological abuse to force them to conform to the rigid disciplinary rules of the school.

In the video, a first-grade class sits cross-legged in a circle on a brightly colored rug. One of the girls has been asked to explain to the class how she solved a math problem, but she has gotten confused.

She begins to count: “One… two…” Then she pauses and looks at the teacher.

The teacher takes the girl’s paper and rips it in half. “Go to the calm-down chair and sit,” she orders the girl, her voice rising sharply.

“There’s nothing that infuriates me more than when you don’t do what’s on your paper,” she says, as the girl retreats.

The teacher in the video, Charlotte Dial, works at a Success Academy charter school in Cobble Hill, Brooklyn. She has been considered so effective that the network promoted her last year to being a model teacher, who helps train her colleagues.

A spokesperson for the charter chain insisted that this was contrary to its rules. The teacher was briefly suspended.

But interviews with 20 current and former Success teachers suggest that while Ms. Dial’s behavior might be extreme, much of it is not uncommon within the network.

Success is known for its students’ high achievement on state tests, and it emphasizes getting — and keeping — scores up. Jessica Reid Sliwerski, 34, worked at Success Academy Harlem 1 and Success Academy Harlem 2 from 2008 to 2011, first as a teacher and then as an assistant principal. She said that, starting in third grade, when children begin taking the state exams, embarrassing or belittling children for work seen as slipshod was a regular occurrence, and in some cases encouraged by network leaders.

“It’s this culture of, ‘If you’ve made them cry, you’ve succeeded in getting your point across,’” she said.

One day, she said, she found herself taking a toy away from a boy who was playing with it in class, and then smashing it underfoot. Shortly after, she resigned.

“I felt sick about the teacher I had become, and I no longer wanted to be part of an organization where adults could so easily demean children under the guise of ‘achievement,’” said Ms. Sliwerski, who subsequently worked as an instructional coach in Department of Education schools.

These complaints sound like they come from a school of the late 19th century. Not the way most parents want their children to be treated. Not the way to prepare for the 21st century, where creativity and independent thinking should be encouraged.