This evening, in a shop in Hayes Valley, I witnessed a woman enter the store and quietly carry out an entire rack of children’s clothing without paying.

The shop-keeper, hearing a slight rustle, turned from me and raced after her, shouting in the street until the woman dropped the merchandise. She returned to her store, triumphant and shaken, as I congratulated her on the confrontation. Her response? “This is the third time today.”

In the end, she was just glad she managed to scare away the shoplifter enough to drop everything on the street. She kept her business safe. For the next several minutes, the shopkeeper was ramped up— and together we watched the video recording of the intruder as she relayed to me the events from this and previous shoplifting attempts.

“After stuff like this happens, I’m just wired. All the adrenaline, you know?

I did know. Just the night before, I had my first experience in confronting a stranger who barged into a happy hour I hosted, then he refused to leave. It was the first time I’ve ever needed to serve the role of “bouncer” — telling someone to leave while stepping in front of them to avoid getting side-stepped. Eventually I stood my ground and backed the intruder a few steps toward the doorway until he finally gave up and left. It was jarring, to be sure.

And while I don’t often have the occasion to confront people in such a direct way, when I returned to my networking conversation at our happy hour, I felt a similar sense of triumph: While under threat, I protected my tribe.

There’s something empowering about the protection instinct that takes over when there’s another person to look after — or in her case, another entity (her business).

The shopkeeper told me that the reason she shouted as she raced after the woman was not to scare the shop-lifter, but to warn the other store clerks on the street. When they hear someone yell, they all race out into the street, taking turns shouting at the person and or snapping a photo of their car’s license plate if need be.

I noticed she kept her boutique shop door wide open and asked her why she didn’t just keep it shut to prevent future incidents. To that, she only shrugged. “If it’s not that, it’ll be something else. This is how it goes here. And what can I say, they love my stuff?”

I realize now this is more about the principle than the logic. Together, the shops in Hayes Valley band together and protect each other when under the attack of petty crime. There’s power in that community.

I’ve noticed this instinct take over in more minimal instances as well. For instance, take my relationship with bugs. If I’m alone and see a cockroach, I’ll freak out, go into “denial” mode, and hide until I can “forget” it’s there. Once I spent an hour watching a cockroach struggle against a spider in my living room as I tried to encourage my cat to kill it. In the end, I left without taking any action and simply went to sleep, closing the bedroom door and hoping it wouldn’t make it through the threshold.

But… if a friend is with me and we see that same cockroach, yet they are more terrified of it than I am, I’ll go into “hero mode” and swiftly kill it without giving it a second thought. This is happened in multiple scenarios for me. How’s that for a paradox?

You may have bravery and courage that stems your own independent efforts and actions. Or you may be like me and have that instinct triggered through something else, like an attack on your people. So while it’s obviously never a pleasant encounter to face malice head-on, as it turns out, it can be a pretty revealing exercise to understand your threat response instinct first-hand. And apparently, you don’t have to go far in San Francisco to get experience in this.