Most of us know about the “fight or flight” response, the body’s built-in survival instinct. But that framework leaves out two other common ways the nervous system reacts to stress. Indeed, psychologists say there are four instinctive reactions that help us understand how people cope with feeling unsafe, overwhelmed or emotionally flooded.

“The ‘four F’s’ ― fight, flight, freeze and fawn ― refer to automatic nervous system responses to a perceived threat,” Caitlyn Oscarson, a licensed marriage and family therapist, told HuffPost. “These are ingrained responses that can show up in traumatic situations, as well as everyday stress and overwhelm.”

The four stress responses occur when our bodies are in survival mode, so we aren’t using the reasoning center of our brains. Thus, we may act in ways that don’t seem logical or reflective of our typical values.

“They’re not personality traits, and they’re not conscious choices,” said board-certified psychiatrist and “Practical Optimism” author Dr. Sue Varma. “They’re automatic survival strategies wired into the brain and body. When someone feels unsafe, overwhelmed or emotionally flooded, the nervous system steps in and tries to protect them the best way it knows how.”