One of the most challenging experiences, under the umbrella of communication in romantic relationships, are partners who have very different internal processing speeds when it comes to both taking in and sharing information with each other.

The reality is, most people will not know for sure how their brain is wired (although many of us think everyone should be able to access the kind of neuropsych assessment that details this). What ends up happening is that without better explanations, people get their wires crossed on the outside, and can end up saying some pretty terrible things to each other.

This article shares one type of better explanation.

All people think and process at different speeds. In couples therapy, and especially when specialized with mixed neurotype couples, we inevitably come across this in our session rooms. Slower processing speed is a brain-based trait (not a formal diagnosis), and it describes how long it takes a person to take in, understand, and respond to information.

A few other helpful facts:

• Slow processing on its own is not about about someone’s intelligence. A person can sit well above average in reasoning and verbal ability while processing more slowly than most of the population, and the reverse combination shows up too.
• Speed also varies within the same person, not just between people. Simple reaction time is sensitive to fatigue, sleep debt and arousal state in ways that have nothing to do with a stable trait (Whats Your IQ, 2025). A partner who processes quickly on a rested Tuesday morning and slowly during a heated exchange after a bad night’s sleep is not being inconsistent about anything meaningful. That is what the same nervous system does under different conditions.
• Age is one of the largest ordinary sources of variation. Processing speed declines steadily across adulthood even in people with no cognitive disorder, and this decline explains a substantial share of the age-related change researchers see in fluid cognitive performance more broadly (Cogn-IQ.org, 2023).
• Slow processing speed and ADHD are highly correlated and co-occur often, particularly with the inattentive presentation, but neither implies the other automatically. A meaningful portion of people with ADHD process at a typical or even fast speed, and a meaningful portion of people with clinically slow processing speed do not have ADHD at all.

As with all invisible brain function can, it can impact your relationships.

In psychotherapy, and in particular working with mixed neurotype couples, there are a few myths that can really cause harm if anyone in the room takes them at face value.

These include the idea that behaviour always communicates intent.

Our job as couple therapists is to help partners read and understand each other more accurately. That premise breaks down pretty rapidly when one (or both!) partner’s brain is processing information at very different speeds, but we aren’t aware thats a variable to consider.

A nervous system working at a different speed can show up as a partner that looks like withholding, carelessness or indifference. Missing that nuance will have a couples therapist validating the wrong story in the room (ADDitude, 2025b; Attention Deficit Disorder Association, n.d.).

The Problem: When Choice Becomes the Default Explanation

Most of us couple therapists are trained first in relational and insight-based models. But we know insight alone doesn’t create change. Change requires both practice and consistency. These frameworks treat behaviour as a product of belief, motivation or trauma rather than executive dysfunction.

What I see, even from experienced therapists, is that explaining the neuroscience behind a behaviour can feel like it is excusing accountability, so therapists hold the line on choice to preserve what they see as necessary tension in the work. The tension isn’t wrong, and it’s okay for human brains to experience stress in learning situations, as long as they simultaneously have emotional safety, especially in the therapy session room.

Consequences in the session room

These invisible variables rarely stay neutral. Once one partner decides a behaviour is a choice, they respond to the meaning they assigned rather than to what actually happened.

That response becomes evidence for the next misread, and the cycle hardens into a relational narrative with little connection to either partner’s actual brain (ADDitude, 2025a). If we do not name the mechanism as therapists, we risk co-signing the narrative instead of creating the conditions for healthy, corrective experiences.

Here is where slower processing and other manifestations of ADHD tend to show up in session.

Taking another look

The pause before speaking. A partner who takes several seconds to respond is often labelled as giving the silent treatment or withholding on purpose. That pause is retrieval time (Davidson Institute, 2021), the brain searching for the right words under time pressure. If one person’s impatience or fast brain is making it feel too intense for the other to have time to process at their own speed, the safety issue in the room has now become palpable.

Walking away mid-argument. Couples therapy narratives have framed this as ‘stonewalling’ or somehow intentionally dodging accountability. Clinically (and physiologically), it is frequently a self-preservation response to overwhelm: a system that has hit capacity and needs to disengage before it can re-engage (Cleveland Clinic, 2023). Stonewalling calls for a conversation about accountability. Overwhelm calls for a conversation about pacing and re-entry, and the two repairs look nothing alike. And John Gottman and Sue Johnson themselves have talked about the antidote here being letting your partner know specifically when the one who needs more time will be ready (calmed down, or re-regulated) to re-visit the issue.

“I don’t know” as an answer. Partners hear this as apathy or a refusal to engage. More often it reflects a brain that cannot generate an answer fast enough under pressure (Borchard, 2024). The better promise in the moment is more like “I don’t know yet.”

Stepping back from blame

Forgetting verbal requests. Partners tend to hear this as evidence their needs did not matter enough to remember. A working memory system that cannot reliably hold a multi-step spoken list explains far more of these moments than motivation does (Attention Deficit Disorder Association, n.d.; Cleveland Clinic, 2023).

Lateness and missed deadlines. This lands as disrespect for someone else’s time. Underneath it is usually a time-estimation deficit, a persistent difficulty predicting how long a task will take (Davidson Institute, 2021).

Rigid adherence to routine. This generally gets interpreted as stubbornness or a need for control, this is frequently a coping strategy for managing the cognitive load of sudden change (Shandley, 2022). The routine regulates the system. It is not necessarily an attempt to control their partner (and that lack of reliable environmental regulation is exactly what contributes to the ongoing cycle of stress without relational safety).

Is it indecisiveness or ‘weaponized incompetence’?

Hesitating over small decisions. This can look theatrical, like stalling for attention. It is often genuine paralysis from weighing options at a slower processing speed, with no strategic intent behind the delay (Borchard, 2024).

Freezing during a sudden emergency. Interpreted as cowardice or a lack of care, this is more accurately a delay in the brain registering and identifying the threat: a timing problem rather than a character problem (Cleveland Clinic, 2023; Shandley, 2022).

Zoning out in fast-moving conversation. The hallmark of an ADHD brain is its inherent inability to sustain attention. It can be seen as boredom or disregard, but rather, this is the brain hitting it’s processing ceiling and going offline temporarily. It has nothing to do with how much the speaker matters (ADDitude, 2025b).

Why This Belongs in the Therapy Room

None of this means intent doesn’t matter. It means intent should be established, not assumed from observations of someone’s behaviour.

A therapist who can name the difference between “they don’t listen to me” and “their working memory drops multi-step requests” gives the couple something they can actually work with, rather than a character indictment neither partner can repair from.

For the partner on the receiving end, this reframe is not permission to stop having needs met. Slow processing speed explains the mechanism behind what’s happening. It obviously doesn’t remove the need for relational scaffolding, what I like to call “love accommodations” and clear communication that both partners can reliably sustain. For the partner whose brain works this way, it is often the first time the behaviour has been named as a brain function rather than a relational flaw.

If you are noticing these patterns in your own cases as a therapist, it is worth asking how they show up in different settings for your clients: at home, at work or in both settings, (since the accommodations will look different in each setting). It is also worth building together a small set of scripts partners can use in the moment, so the correction happens in real time rather than after the damage has already set in.

What the Evidence Actually Says

• The pause before speaking is retrieval time (Davidson Institute, 2021),
• Walking away mid-argument is frequently an automatic self-preservation response to overwhelm rather than a refusal to engage (Cleveland Clinic, 2023),
• “I don’t know” often means the brain cannot generate an answer fast enough under pressure (Borchard, 2024),
• Forgetting verbal requests reflects a working memory limit more than it reflects disregard (Attention Deficit Disorder Association, n.d.),
• Lateness often stems from a time-estimation deficit rather than a lack of respect (Davidson Institute, 2021),
• Reaction time variability is itself a documented ADHD feature, and it is not evidence of manipulation (Thorsen et al., 2018),
• Processing speed improves with medication for many ADHD adults, which supports a neurological basis over a motivational one (Klarity Health, 2025).

Solutions for the Couple

Which partner do we focus on first? The reality is, the relational accommodation initially sits primarily with the faster processor. Asking someone mid-lag to narrate their own lag defeats the purpose (kinda like needing scissors to open the plastic wrapped new scissors).

The hardest part for the faster processor is building in latency as a default rather than a favour.

1. Ask one question at a time,
2. Resist filling silence with a second or third version of the same question, and
3. Treat a pause as the answer being assembled rather than as a stall (Love on the Autism Spectrum, 2026),

Share the topic before a hard conversation happens. Pre-processing time changes the quality of a response more reliably than pressure does (Upbility Publications, 2025).

Watch for the pattern this speed gap tends to create. The faster partner pushes for an immediate answer, the slower partner either freezes or gives a premature agreement that later falls apart, and each ends up reading the other as the problem (Grey, 2022). Naming the pace mismatch out loud, without rushing to fix it, interrupts that cycle before it repeats.

This is relational work. None of it removes the slower partner’s responsibility to eventually respond and follow through to the stated emotional needs and requests of their partner, but it changes the conditions under which that response becomes possible.

Solutions for the Therapist

The foundational lens for any couples therapist is the Dual Lens Approach, first described by our ADHD couples therapist John Foulkes. The Dual Lens Approach means you must simultaneously hold and explore both the neuroscience and the psycho-emotional explanations at the same time. In every session.

Assess before assuming. When lateness, silence or hesitation recurs and does not shift with insight or motivation, that gap between effort and outcome is diagnostic information in its own right, since slow processing speed is a measurable construct distinct from ADHD that can compound it (Springer Nature Link, 2020).

Hold two explanations at once: a behaviour can be both meaningful and mechanistically slow. Watch for masking specifically. What presents fluently in session may not reflect capacity at home, so the partner’s collateral report carries as much weight as what you observe in the room.

Keep up with new research and neurodivergent affirming approaches in your continuing education. For mixed neurotype couples and families, check out the original DIY*ADHDCouples for couple therapists, which outlines AaRT, the techniques to adapt your chosen intervention for neurodivergent clients. Make sure you have access to ADHD specialized clinical supervision or consultation.

For Clients

Interested in talking to an ADHD trained and experienced couples therapist?

Read more about mixed neurotypes in romantic relationships, as well as in parenting and family life.

References

ADDitude. (2025a, May 9). How to fix a relationship: 9 solutions from ADHD couples. https://www.additudemag.com/how-to-fix-a-relationship-problems-adhd-solutions/

ADDitude. (2025b, July 19). Slow processing speed: Signs & solutions for a misunderstood deficit. https://www.additudemag.com/slow-processing-speed-adhd-interventions/

Attention Deficit Disorder Association. (n.d.). Executive function disorder. add.org

Borchard, T. (2024, June 11). Are you a slow processor? Psychology Today. https://www.psychologytoday.com/us/blog/the-intelligent-divorce/201501/are-you-a-slow-processor

Cleveland Clinic. (2023). Executive dysfunction. clevelandclinic.org

Cogn-IQ.org. (2023, October 26). Processing speed and IQ: Correlation and the Gs factor. https://www.cogn-iq.org/blog/processing-speed-iq/

Cogn-IQ.org. (2026a, March 20). Attention to detail tests: What perceptual speed (Gs) measures and what it predicts. https://www.cogn-iq.org/blog/attention-to-detail-tests/

Cogn-IQ.org. (2026b, June 8). WAIS: The Wechsler Adult Intelligence Scale (WAIS-IV & WAIS-5): Structure, scores & interpretation. https://www.cogn-iq.org/learn/tests/wechsler-adult-intelligence-scale/

Davidson Institute. (2021). Understanding, diagnosing, and coping with slow processing speed. davidsongifted.org

Grey, J. (2022, June 4). Connect fast vs slow communicators. Healing Couples Retreats. https://healingcouplesretreats.com/connect-fast-vs-slow-communicators/

Klarity Health. (2025, November 5). Why your brain freezes: Understanding ADHD processing speed and communication challenges. https://www.helloklarity.com/post/why-your-brain-freezes-understanding-adhd-processing-speed-and-communication-challenges/

Love on the Autism Spectrum. (2026, May 7). Effective communication in neurodiverse relationships. https://www.loveontheautismspectrum.com/effective-communication/

Mackenzie, G. (2026, February 18). ADHD and processing speed. Navigate ADHD. https://www.navigateadhd.org/blog/adhd-and-processing-speed

Shandley, K. (2022). Processing speed: The hidden cognitive bottleneck. Affirmative Minds Psychology. affirmativemindspsychology.com.au

Springer Nature Link. (2020, September 11). Slow processing speed: A cross-disorder phenomenon with significant clinical value, and in need of further methodological scrutiny. European Child & Adolescent Psychiatry. https://link.springer.com/article/10.1007/s00787-020-01639-9

Thorsen, A. L., Meza, J., Hinshaw, S., & Lundervold, A. J. (2018). Processing speed mediates the longitudinal association between ADHD symptoms and preadolescent peer problems. Frontiers in Psychology, 8, 2154. https://doi.org/10.3389/fpsyg.2017.02154

Upbility Publications. (2025, November 6). Slow processing speed: Your essential guide to understanding what it is and effective strategies to support it. https://upbility.net/blogs/news/slow-processing-speed-your-essential-guide-to-understanding-what-it-is-effective-strategies-to-support-it

Whats Your IQ. (2025, September 3). Processing speed: Importance and improvement strategies. https://whats-your-iq.com/en/articles/cognitive-psychology/processing-speed-why-it-matters-and-how-to-improve-it