Slow Breathing Made People Take More Risks, Not Fewer, in a Berlin Brain-Scan Study

Under the long-exhale condition participants accepted the risky option significantly more often. The change was driven by heightened sensitivity to the potential reward rather than by reduced concern about the potential loss; the volunteers were not becoming reckless about downside so much as more drawn to upside. Those whose heart rate variability rose most during slow breathing, a marker of the parasympathetic branch of the nervous system taking over, also showed the strongest reward-related activity in two regions: the ventromedial prefrontal cortex, which assigns value to options, and the precuneus, which is involved in integrating bodily signals into self-referential thought. The authors' interpretation is that the interplay between breathing and cardiac rhythm makes the brain more receptive to rewards.

What to make of it

It is a well-designed study and a small one. Forty-one young, healthy volunteers making laboratory bets in a scanner is a long way from a trader on a desk or a driver on a motorway, and the authors say so, noting that future work will need to test broader populations. The finding also cuts against a good deal of the folk wisdom sold with breathing practices, which promise composure and imply prudence. What the data shows is composure without prudence: the body relaxes, the threat system quietens, and the reward system, no longer competing with anxiety for attention, gets louder.

That is not necessarily bad. Anxiety makes people avoid choices they would benefit from taking, and a technique that restores appetite for a reasonable risk is useful to someone who freezes. It is a reason to be precise about what slow breathing is for. It is a tool for reducing arousal. It is not a tool for improving judgement, and the two are not the same thing, a distinction that matters for anyone using it before a negotiation, a trade or a difficult conversation.

The paper is one of a small number of controlled studies of what slow breathing actually does inside the body, as opposed to what it is claimed to do. Our review of that evidence, including the blood pressure data and the limits of the trials behind it, is in the piece on pranayama and the research; the broader question of what meditative practice can and cannot be shown to deliver is in our piece on meditation's benefits and harms. This study adds a genuinely new finding to that file, and a caution: when you feel calmer after a long exhale, you may also feel more like saying yes. Decide whether that is what you wanted before you breathe.