But Sarah Friar, who became Nextdoor CEO in 2018 after serving as CFO of Square, thinks her platform has learned valuable lessons as it works to balance open dialogue with civility. At Fortune’s Most Powerful Women summit Wednesday, Friar said those insights could help not just other tech companies, but also any company looking to upgrade its internal culture.

Some of Nextdoor’s interventions seem remarkably simple. For instance, users are now asked to agree to a “neighborhood pledge” including commitments to kindness and non-discriminatory behavior. And a “Kindness Reminder” pops up to notify users if what they’re writing seems likely to face review. Nextdoor is also adding a new role for volunteer “community reviewers,” a role Friar says has attracted volunteers who “tend to more reflect the diversity of [their] neighborhood” compared to Nextdoor moderators.

Those measures, many shaped in collaboration with social scientists, are showing real effects. For instance, Friar says one-third of the time, users who receive a Kindness Reminder edit their posts to remove insulting language.

Such nudges are preferable to simply letting moderators decide after the fact which content gets deleted and which can stay.

“What we didn’t want to do was shut people down,” Friar told Fortune’s Ellen McGirt, “because … we believe there is a really big place for people not being stuck in thought bubbles with their friends or colleagues, people who largely agree with them … People can disagree without being disagreeable.”

Fostering civil disagreement, in turn, is crucial to Nextdoor’s larger mission of strengthening communities and fighting long-rising social isolation, which the the coronavirus pandemic has sharply worsened.

“A lot of people are talking about being lonely,” said Friar of recent conversations with users. “I was hearing it from people in Australia, people in France … and it actually didn’t matter what age and what demographic you came from.”

Isolation increases the risk for a plethora of physical and mental health problems, ranging from depression and obesity to drug addiction. Friar predicts that combating isolation will become a major priority in the 2020s, which she compared to the way Jane Fonda raised awareness of the benefits of exercise in the 1970s.

The new emphasis on community, Friar predicted, will also apply to companies. For instance, she speculated that the kind of cautionary nudges Nextdoor gives its users could also help make emails within companies kinder. And she offered her own practice of having regular informal discussions with rank-and-file employees as an example of how good communication can cement bonds within a company.

“What we’ve learned with neighbors is, start small,” Friar said. “Often it’s these small moments that win people’s hearts, not just their minds.”