Why Some People Keep Secrets: Dismissive Avoidant Attachment and the Origins of Infidelity
You replay the dinners and the vacations and wonder how he could sit there. Dr. Stan Tatkin on the attachment pattern underneath secret keeping — and why repair has to go deeper than a promise to be honest.
By Duane Osterlind, LMFT, CSAT-S
If you're the partner who kept secrets — the one who lived a double life, who held an entire hidden world apart from your relationship — you may have spent a lot of time asking yourself: Why am I like this? Why was it so easy to compartmentalize? Why didn't I just tell the truth?
In Part 3 of my conversation with Dr. Stan Tatkin, he traced the capacity for secret keeping back to its origins. And the answer might be the first time someone has explained your internal world back to you in a way that actually makes sense. This doesn't excuse the behavior — not even close. But it does help explain what you're working with, so you can actually change it. Because as Stan would put it: you can't change what you can't see.
The Attachment Style Underneath Secret Keeping
Stan identified a specific attachment pattern that shows up in many of the people who develop the capacity for sustained deception in their relationships: dismissive avoidant attachment. And he traced it all the way back to infancy.
Here's how it develops. A child reaches for connection — attention, comfort, attunement — and that reaching isn't met. Not because the parents are abusive, but because they're emotionally unavailable. Distant. Preoccupied. Maybe well-meaning, but not actually present in the way an infant's nervous system needs. The child learns something. They learn that reaching out doesn't work. So they stop reaching. They go underground.
Stan was clear about what “going underground” means at a developmental level. The child learns to auto-regulate. To keep things internal. To not bring their emotional life into relationship with anyone, because relationship has been proven — to their developing nervous system — to be an unreliable source of co-regulation.
It's not because they're choosing to deceive. It's because it's the only adaptation they've ever known.
— Dr. Stan Tatkin (paraphrased)
How This Pattern Shows Up in Adult Relationships
Fast forward thirty or forty years. The infant who learned to auto-regulate is now an adult in a committed relationship. And the pattern is still running. They struggle to bring their internal world into the relationship. They handle things alone. They don't tell their partner when they're struggling. They develop a robust internal life that operates separately from the shared life of the relationship.
And then — if other risk factors are present — that internal life can include things their partner doesn't know about. Affairs. Pornography use. Financial deception. Sexual acting out. The capacity for compartmentalization that protected them as a child becomes the architecture of a secret life as an adult. This isn't a moral failing. It's a developmental adaptation that was once useful and is now causing devastating harm. Both of those things can be true at the same time.
Why This Pattern Is Harder to Change
Here's what Stan said that I think is the most clinically important point in this section: people with dismissive avoidant attachment have a harder prognosis than people with other patterns — not because they're more damaged, but because they don't know what they've been missing.
Think about that for a second. If you grew up reaching for connection and getting hurt, you at least know connection exists — you're just afraid of it. But if you grew up never reaching at all, never expecting connection, never knowing what attuned co-regulation feels like — you don't know what's been absent from your life. You think the way you experience relationships is just how relationships work. That's the part that makes the work so hard. You can't fix what you don't recognize as broken.
What Can Actually Change This Pattern
Stan said something else in this part of our conversation that I keep coming back to: “It's over. As you thought this was. It's gotta be a complete rebuild.” The relationship the person had before discovery was built on the dismissive avoidant pattern. They could keep secrets because nothing in the system required them not to. Going forward, that's not an option anymore. The entire architecture has to be different.
That means the person who kept the secrets has to do something they've never done before in their life: bring their internal world into relationship. Consistently. Without curating it. Without holding back the parts that feel risky to share. Without going underground when things get hard.
This is the work. And it cannot be done alone. As Stan emphasized throughout our conversation, the only way to rewire dismissive avoidant attachment is through repeated experiences of safe, attuned, co-regulated connection — with a therapist, with safe friends, with a partner who is willing to do the work alongside them. You can't think your way out of an attachment pattern. You have to experience your way out of it.
What This Means for the Work Ahead
If you're the person who kept the secrets and you recognize yourself in this description, I want you to hold two things at once. Yes, this is an explanation of how you got here. No, it does not excuse the harm you caused. Both things have to stay true at the same time.
The good news — if there is good news here — is that attachment patterns can change. Not easily. Not quickly. But they can. And the change happens through exactly the thing your nervous system has been avoiding your whole life: showing up in relationship, telling the truth, staying connected when shame wants you to retreat.
This is the heart of what we work on in the Shame to Resilience workshop. Building the capacity to stay in relationship when every instinct says to go underground. Learning to bring your internal world to the surface, even when it feels dangerous.
In Part 4 — the final part of my conversation with Stan — we get into shame itself. The difference between guilt and shame, why leading with shame actually makes things worse for your partner, and what to do instead. That's where the practical tools are.
Watch the full series
Part 1: What Betrayal Does to the Brain
Part 2: Boundaries as Good Faith Effort
Part 3: Attachment and the Origins of Secret Keeping (this post)
Part 4: Shame, Guilt, and the Path Forward
About Dr. Stan Tatkin: Developer of PACT (Psychobiological Approach to Couples Therapy) and author of Wired for Love and In Each Other's Care. Learn more at thepactinstitute.com
What Betrayal Does to the Brain: Dr. Stan Tatkin Explains Why You Can't Stop Asking Questions
PACT developer Dr. Stan Tatkin explains why discovery of betrayal hijacks the brain, why obsessive questioning is biological, and why partners can’t “just move on.”
If you’ve discovered your partner’s betrayal and you can’t stop asking questions — if you’re up at 3 a.m. replaying every holiday, every conversation, every moment you thought was real — there is nothing wrong with you. Your brain is doing exactly what it’s designed to do.
I recently sat down with Dr. Stan Tatkin, the developer of PACT (a psychobiological approach to couples therapy) and the author of Wired for Love and In Each Other’s Care. Having completed his Level 1 training myself, I can tell you it changed how I do couples work. And what he shared about what’s happening in the brain after betrayal is discovered is some of the clearest, most validating information I’ve heard on this topic.
Let me walk you through it.
First, What Actually Counts as Betrayal?
Stan made an important distinction at the start of our conversation. People use the word “betrayal” for all sorts of things — your partner buying something they said they wouldn’t, telling someone a secret they had no right to share. Those things hurt, but they don’t produce the kind of neurological injury we’re talking about here.
The kind of betrayal that creates trauma is something specific. As Stan explained, it’s the discovery of vital information that you had a right to know but were deprived of — information that, once discovered, changes everything: who you thought you were, who your partner is, what’s true, what’s not true, and your identity within the relationship.
The major violation is the lack of free flow of information — omission, lying by omission on something big. That’s what does the damage. — Dr. Stan Tatkin
This matters because it reframes the wound. The sexual element of an affair isn’t pleasant, but it’s not actually what produces the trauma response. The deception is. The systematic withholding of information that the betrayed partner had every right to know is what hijacks the nervous system.
What Happens in the Brain at Discovery
When that vital information lands, the discovery partner experiences a measurable set of symptoms that mirror PTSD. Stan listed them clearly: mood instability, sleep problems, flashbacks, paranoia, thoughts that won’t go away, questions that have to be asked, and the disorienting feeling of “sleeping with the enemy” — of no longer being able to know the person they thought they knew.
This isn’t a judgment. It isn’t a personality flaw. As Stan put it, this happens by proof — it just is a fact.
And here’s the part that I think is the most important thing he said. The brain doesn’t ask your permission to do this.
My brain will automatically re-sort this new data, and it will be busy for quite some time — especially if it was back in the beginning. — Dr. Stan Tatkin
The new information intrudes on every memory the betrayed partner has of the relationship. It has to be re-sorted. Every birthday. Every anniversary. Every conversation. Every “I love you.” The brain runs this process automatically, without conscious choice, because it has to reconstruct who you are, who your partner is, and what your shared history actually means.
Stan was direct about this: people who judge the discovery partner for being “still upset” or “still perseverating” months after discovery are missing the science. The mind can’t do anything else. In the first year especially, this is what every brain does when it encounters this level of identity-shattering information.
Why You Can’t Stop the Questions
In our conversation, I shared a way I often think about this: to know our environment is to keep ourselves safe. If we can’t know our environment, we can’t predict our environment. And if we can’t predict our environment, our brain can’t get to a state of safety — because it doesn’t know what to do.
Stan agreed. He pointed out that humans aren’t actually safe most of the time — we just have a denial system that protects us from thinking about it constantly. After betrayal, that denial system collapses. And the brain goes into overdrive trying to rebuild a coherent picture of reality.
That’s why the questions don’t stop. The brain isn’t trying to torture anyone. It’s trying to gather enough data to reorganize the file system. To answer: Who is this person, really? What was true? What was a lie? Can I predict what they’ll do next? Until those questions have answers — honest, complete, consistent answers — the brain will keep asking.
What This Means for Your Healing
If you’re the betrayed partner reading this, I want you to hear what Stan said: you’re not crazy. You don’t have a personality disorder. You’re not being dramatic. Your nervous system is responding to a real injury in the way nervous systems are designed to respond.
And if you’re the person who caused the betrayal, this is the part that matters: you cannot talk your partner out of this process. You cannot reason them out of it. You cannot apologize them out of it. Their brain has to do its job, and your job is to provide the consistent, honest, predictable behavior that gives their brain enough data to eventually let down its guard.
I break down the specific neuroscience of this — what happens in the amygdala, hippocampus, and prefrontal cortex — in our complete guide to the neurobiology of betrayal trauma. And if you want to understand the symptoms your partner is experiencing through a clinical lens, I cover that in Why Betrayal Trauma Feels Like PTSD.
In Part 2 of my conversation with Stan, we get into something that I think is even harder to hear but just as important: boundaries. Not as punishment, but as the mechanism that actually gives relationships a chance to heal. I’ll link to that next.
Watch the full series:
Part 1: What Betrayal Does to the Brain (this post)
Related reading:
About Dr. Stan Tatkin:
Dr. Stan Tatkin is the developer of PACT (Psychobiological Approach to Couples Therapy) and the author of Wired for Love and In Each Other’s Care. Learn more at thepactinstitute.com
Why Betrayal Trauma Feels Like PTSD (Because It Actually Is)
If you’ve discovered your partner’s betrayal and feel like you’re losing your mind, I want you to know: you aren't crazy. You're injured. Research shows that 60-70% of betrayed partners meet the criteria for PTSD, meaning your sleepless nights and intrusive thoughts aren't "drama"—they are legitimate responses to a traumatic brain injury.
In this post, we explore the neuroscience behind your pain, explaining why your "alarm system" is stuck in overdrive and why you can't just "get over it." But more importantly, we discuss neuroplasticity and the scientific proof that your brain can heal. Recovery is possible, and it starts with understanding that your reaction is a normal response to an abnormal situation. Read on to find validation, science-backed insights, and a roadmap back to yourself...
If you have discovered your partner's infidelity or sexual betrayal, you might feel like your world has tilted on its axis. You can’t sleep. You can’t eat. You find yourself obsessively checking their phone or tracking their location. You might be having panic attacks or feeling a rage you’ve never known before.
This post is a companion to the complete betrayal trauma guide.
And perhaps the most frightening thought creeping in is: "Am I losing my mind?"
I want to look you in the eye—metaphorically speaking—and tell you something crucial: You are not crazy. You are not "being dramatic." You are experiencing a legitimate, physiological response to trauma.
Research indicates that between 60% and 70% of partners who experience betrayal meet the full clinical criteria for Post-Traumatic Stress Disorder (PTSD). What you are feeling isn't just heartbreak; it is a traumatic brain injury. Understanding this biological reality is the first step toward compassion and healing.
Download The Worksheet
Betrayal is Trauma, Not Drama
When we think of PTSD, we often picture combat veterans or survivors of physical accidents. But emotional betrayal by an intimate partner strikes at the very core of our survival instincts. We are wired for connection. When the person who is supposed to be your safe harbor becomes the source of danger, your brain’s safety systems go haywire.
It’s heartbreaking to see so many betrayed partners blaming themselves for their inability to "just get over it." You might wonder why you’re still triggering months later, or why you can't stop asking the same questions.
This isn't a character flaw. It’s neurology. Just as you wouldn’t expect a broken leg to heal in a week by simply "thinking positive," you cannot expect a traumatized brain to snap back to normal overnight. Recovery takes time—often 18 to 24 months for acute symptoms to stabilize, and 3 to 5 years for full integration.
That timeline might sound daunting, but knowing it can be a relief. It means you aren't failing at recovery; you are right on schedule for a major injury.
Your Brain on Betrayal: The Three Key Players
To understand why you feel this way, we need to look at three specific regions of your brain that are profoundly affected by trauma.
1. The Amygdala: The Alarm System
The amygdala is your brain's threat detection center. It’s like a smoke detector scanning for danger. When you discover betrayal, this alarm gets stuck in the "ON" position. It becomes hyperactive and sensitized.
This is why you feel constant anxiety, hypervigilance, and that jittery sensation that you can never truly relax. Your body is flooded with stress hormones like cortisol and adrenaline, keeping you in a perpetual state of fight, flight, or freeze. You aren't being paranoid; your nervous system is desperately trying to protect you from another surprise attack.
2. The Hippocampus: The Memory Center
The hippocampus is responsible for processing memories and filing them away as "past events." When trauma hits and cortisol floods your brain, the hippocampus gets impaired. It stops filing properly.
This results in intrusive flashbacks, nightmares, and obsessive rumination. Your brain is trying to process an event that feels too big to file away. Instead of becoming a dusty memory on a shelf, the trauma stays on your mental desktop, open and active. This is why you replay details over and over—your brain is trying to make sense of a narrative that has been shattered.
3. The Prefrontal Cortex: The CEO
This is the part of the brain responsible for logic, emotional regulation, and decision-making. During trauma, blood flow and energy are diverted away from this "thinking brain" and sent to the "survival brain" (the amygdala). Your inner CEO essentially goes offline.
This explains the "brain fog," the difficulty concentrating, and the emotional mood swings. If you feel like you don’t recognize yourself—like you’ve lost your ability to be calm or rational—it’s because your executive function is temporarily impaired.
The Six Core Trauma Responses
Once we understand the brain science, your behaviors start to make a lot more sense. These aren't symptoms of being "controlling" or "weak"; they are the six core responses to betrayal trauma.
Hypervigilance: Scanning for threats, checking phones, monitoring bank accounts. This is your amygdala screaming for safety.
Intrusive Thoughts: Flashbacks and obsessive thinking. This is your hippocampus struggling to process the reality of what happened.
Avoidance: Staying away from places, songs, or shows that remind you of the betrayal to avoid pain.
Emotional Dysregulation: Intense mood swings, rage followed by despair. Your prefrontal cortex is struggling to regulate your feelings.
Dissociation: Feeling numb, foggy, or like you are watching your life from the outside. This is your brain's way of distancing you from overwhelming pain.
Functional Impairment: Struggling to work, parent, or take care of daily tasks.
If you see yourself in this list, take a deep breath. You are reacting exactly as a human brain reacts to deep trauma.
Why This Reframe Changes Everything
Why does it matter that we call this trauma? Why not just call it a "relationship issue"?
Because understanding this as a brain injury changes how you treat yourself. It allows you to trade shame for self-compassion. Instead of beating yourself up for checking his phone again, you can say, "My amygdala is terrified right now and looking for safety."
It also changes how you approach treatment. You wouldn't treat a broken bone with a band-aid. Trauma requires trauma-informed care—individual therapy, nervous system regulation, and safety—before effective couples counseling can usually begin.
Most importantly, it validates your pain. You aren't overreacting. You are injured.
And here's what actually builds safety — three actions, not just words.
Hope: Your Brain Can Heal
I want to leave you with the most important piece of science: Neuroplasticity.
Neuroplasticity is your brain's amazing ability to rewire itself. The damage caused by betrayal is not permanent. With the right support, safety, and time, your amygdala can learn to stand down. Your hippocampus can file these memories away where they belong—in the past. Your prefrontal cortex can come back online, restoring your sense of self.
You can heal. You can trust your gut again. You can feel joy again.
Recovery is a marathon, not a sprint. But every time you offer yourself kindness instead of judgment, every time you reach out for safe support, you are helping your brain repair those pathways. You are moving from brokenness toward resilience.
Need more support?
If you are struggling with the symptoms of betrayal trauma, you don't have to do it alone.
Download our Free Guide: Understanding Your Trauma Response
Listen to the Podcast: The Addicted Mind Podcast
Learn about Therapy: Novus Mindful Life