As a mediator, I often observe lawyers providing advice to or discussing options with their clients, particularly in the final stages of negotiations. In sensitive claims with strong underlying emotions, it is not uncommon to see lawyers present clear legal analysis to clients, yet the clients do not seem to absorb it. Not because the advice was flawed, but more often, because the client has moved outside their “window of tolerance”. When that happens, the thinking part of the brain goes offline.
A plaintiff agrees to something in hypoarousal that they later regret. A defendant becomes so fixated on a particular outcome that they underestimate their risks and refuse to consider what appear to be commercial offers. The lawyers then spend hours repeating the legal analysis and negotiating with clients who are, neurobiologically, in survival mode. When a client is in survival mode, they don’t need more rationale and logic. They need support to return to their window of tolerance so their thinking brains can come back online.
The challenge? Most lawyers track legal risk, not arousal levels. But if you can spot the early signs that someone is leaving their window of tolerance, you can prevent breakdowns before they occur.
What is the Window of Tolerance?
The window of tolerance is a concept developed by Dr. Dan Siegel to describe the range of arousal where a person can remain connected, think clearly, and process all information presented to them, even under stress.
Inside this window, your client can reflect, ask questions, consider options, and tolerate uncertainty under pressure. Their breathing is relatively even. They can make eye contact. Their speech is coherent and goal-directed. This is the zone where a client is most likely to understand and absorb the legal advice provided to them.
Understanding this concept isn’t just good practice; it sits at the heart of a lawyer’s ethical obligations. You need your client to be able to provide informed instructions. When they’re outside their window of tolerance and acting in “survival mode”, that capacity is compromised.
In mediations, I tend to see parties leave their window in one of two directions:
- When arousal rises above the window, the party moves into hyperarousal: fight or flight. You’ll often see rapid breathing, tension, and clenched fists. They might talk over you, jump topics, or make impulsive decisions (“Just take it, I don’t care”.) Their thinking becomes binary.
- When arousal drops below the window, the party moves into hypoarousal: freeze or shutdown. They may slump in their chair. Their voice goes monotone or trails off. They give one-word answers. They might say, “Whatever you think,” while looking detached. Later, they may have little memory of what was discussed.
When someone is trauma-affected, or under other forms of stress (personal or work-related), their window of tolerance is usually narrow. Place that person in a mediation, or other form of negotiation, and you add a whole other layer of triggers: listening to a claimant’s personal experience, hearing and opposing sides’ legal argument, time pressures, reserve pressures, being challenged or disbelieved. It doesn’t take much to push someone out of their window of tolerance.
Why Lawyers Need to Track This
Clients operating outside their window may appear to be participating, but they’re not, at least not fully.
The hyperaroused client who snaps “fine, whatever” isn’t making an informed decision—they’re attempting to escape overwhelm. The hypoaroused client who nods quietly isn’t weighing options; they’ve disengaged.
In both states, legal reasoning capacity is compromised. Instructions given in these moments may lack informed consent.
In a recent mediation, where the plaintiff faced significant liability hurdles, they arrived with settlement expectations based on what they’d heard others had received. When it became apparent that the defendant’s position was vastly different to the expectations the plaintiff arrived with, the plaintiff became increasingly irrational, insisting on running to trial one moment, then prepared to walk away entirely the next.
The plaintiff was oscillating between hyperarousal (agitated, wanting to fight) and hypoarousal (capitulating, wanting to collapse). Instructions were not being provided in a way that could confidently be described as informed or rational.
The mediation was adjourned to give the plaintiff time to re-regulate. This wasn’t just good trauma-informed practice; it was an ethical obligation. Both lawyers and mediators have an ethical obligation to ensure that informed decision-making occurs. While a client’s right to self-determination and agency is paramount, it is equally important to ensure that any instructions are given in an informed decision-making process.
Long before dysregulation becomes obvious, there are usually subtle signs that someone is drifting toward the edge of their window.
What to Watch For: The Early Edge Signs
This is not what dysregulation looks like once it’s obvious; it’s what it looks like just before it happens. Most lawyers wait until dysregulation is obvious. By then, you’re in damage control. The key is catching the micro-shifts before someone fully exits their window of tolerance. These micro-shifts are your optimal moment to intervene. Suggest a break. Change the task.
Some early signs you may observe are:
- Approaching hyperarousal: shoulders tightening, fidgeting, faster speech, black-and-white statements.
- Approaching hypoarousal: gaze drifts away, longer silences, speech slows, comments like “I’m tired.”
When I observe these early signs, I tend to engage in the opposite behaviour. For example, someone’s speech is getting faster and louder, so I tend to speak slower and softer to bring them back down into their window. If their speech is slowing and they seem to be drifting away, I may speed up their engagement with lots of short, fast comments, or give them a task to do (even something as small as passing me something on the table), to get them moving.
Once you start noticing arousal, it changes how you think about the mediation as a whole, not just what happens in the room, but how you prepare, how you pace the day, and when you decide it’s time to slow things down.
What You Can Do Before Mediation
In my experience, the most effective plaintiff lawyers, with their client’s permission, have assessed their client’s baseline window before mediation (a lawyer acting for an institution or insurer will rarely do this by virtue of the nature of that lawyer/client relationship).
The initial baseline check takes five minutes.
- Ask your client about their stress response: “When stressed, do you get wound up, or shut down?”
- Use a simple scale: “If 0 is shut-down, 5 is stressed-but-okay, and 10 is panicky, where are you now?”
- Identify warning signs: “What are the first signs in your body that you’re getting too stressed?”
- Note triggers and buffers: “What has made past legal meetings harder? What has helped?”
Make a note to look out for any of those signs as the mediation takes place, and plan the harder conversations around these patterns.
What You Can Do During Mediation
During the mediation, this is less about doing something new and more about pacing what you already do, based on where your client is sitting in their window. For example:
- Track a client’s arousal as closely as you track BATNA. Notice which topics or process moves push your client toward their edges.
- Pace your advice. Reserve complex risk analysis for periods when your client is clearly within their window.
- Use breaks as regulation tools. When you observe edge signs, call a break. Ten minutes can reset the nervous system.
- Check comprehension after dysregulation. “We talked about X just before the break. Can you walk me through what you understood?”
When to Slow or Stop
There are times when continuing with the mediation is unhelpful and doing so risks compounding harm or undermining informed decision-making. For example, moments such as these may indicate that the mediation should pause or terminate:
- Escalating anger or panic that doesn’t settle.
- Dissociation, they describe feeling “far away” or being unable to recall what was said.
- Compliance without engagement, they can’t explain decisions in their own words.
- Inability to follow simple explanations, or sudden position shifts after visible overwhelm.
- Any mention of self-harm or hopelessness.
These are red flags that arousal is too high or too low for genuine participation.
A Final Thought
Some lawyers initially resist this approach. “We don’t have time for all that,” “I’m not their therapist”, or “I’m not a mind reader.”
But when clients stay within their window, mediations progress faster. Advice lands. Decisions stick. When clients operate outside their window, you’re negotiating with someone whose capacity is compromised. That creates practical and ethical problems.
Being aware of the concept of a “window of tolerance”, and tracking when someone may be moving out of it, helps lawyers (and mediators) understand what’s happening with their clients in high-stress moments, and it impacts your ability to obtain informed instructions.
In sensitive claims, tracking your client’s window may be the most important thing you do on mediation day. Without it, you’re not acting on instructions. You’re acting on survival responses dressed up as decisions.