What Is… The Diving Reflex

The diving reflex: tap into your inner dolphin: a quick way to calm down the nervous system

In this series, I dig a little deeper into the meaning of psychology-related terms. This week’s term is the diving reflex. While the reflex itself has nothing to do with psychology, it’s actually still relevant.

The diving reflex is present in all mammals to some extent. It triggers a number of physiological changes that allow us to spend longer periods of time underwater. Does anxiety help prolong your dolphin time? Nope, so the body does what it can to shut that nonsense down.

In humans, including infants, this reflex is triggered when we hold our breath and put our face (and specifically our nose) in cold water. Sensory receptors in the face and nose tell the brain what’s going on, and the brain responds by slowing the heart rate by 10-25%, decreasing blood flow to the periphery, and increasing blood flow to the heart and brain.

The diving reflex and mental state

All of this happens as a reflex; there’s no conscious thought required. The parasympathetic nervous system, and specifically the vagus nerve, take care of it for you. If your anxiety is spiking and you’re approaching a panic attack or you’re feeling totally dysregulated, this could be a quick way to settle things down in the body.

The diving reflex is also involved in the dialectical behaviour therapy (DBT) TIPP acronym. The T is for temperature change, which involves sticking your face in a sink full of cold water, setting off the reflex.

Anxiety and hyperventilation

On a vaguely related note, let’s talk breathing and anxiety. While thinking about your breathing in the midst of extreme anxiety or panic may seem about as reasonable as trying to meditate during a riot, there’s actually a good biological reason to get your breathing under control.

When we breathe, we need oxygen coming in and carbon dioxide going out. When you hyperventilate, as often is the case with intense anxiety, you’re blowing out a lot of carbon dioxide. Even though you need to breathe in oxygen, your brain doesn’t decide if you’re breathing properly based on how much oxygen is inside of you; it makes that call based on how much carbon dioxide there is. Part of why your brain cares about carbon dioxide so much is that it can throw off the pH balance in your blood. If you’re blowing off too much carbon dioxide, red flags start flying in your brain, screaming out that you can’t breathe. If you weren’t anxious before, you sure as hell are now.

To counteract this, slow the breathing way down, especially the exhales. Breathing out through pursed lips can slow the speed that you’re releasing CO2. You could also do the old-school breathing into a paper bag trick, which allows you to re-inhale CO2. This may not relieve your anxiety, but it will stop you from shooting yourself in the foot.

Using your body to your advantage

Our bodies are truly remarkable things. Sometimes, the things they do automatically can make things worse, but knowing the right tricks can help you take advantage of your automatic responses. Have you experienced either of these effects and found it made a difference in your mental state?

Source: Wikipedia: Diving reflex

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The Psychology Corner has an overview of terms covered in the What Is… series, along with a collection of scientifically validated psychological tests.

Ashley L. Peterson headshot

Ashley L. Peterson


Ashley is a former mental health nurse and pharmacist and the author of four books.

27 thoughts on “What Is… The Diving Reflex”

  1. Many years ago I used the paper bag trick for the first time by a doctor, because of my first hyperventilating incident when me and mum thought it was something else.
    It certainly works.

    Since then, I have had some attacks, but no paper bag, but used the cupped hands technique. Which again, that doctor told me about that while I was breathing into the paper bag.

    I have automatically, without thought used pursed lips, without thinking.

      1. Yes, it is.
        It wasn’t until I read the pursed lips part in your post though that I thought, I do that. So that’s how automatic, that is for me.

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