By Paul Thagard, University of Waterloo

Tai chi is an ancient Chinese tradition that provides a gentle and graceful form of exercise. I’m now on my second course and really enjoying it, even though my Apple Watch says tai chi does not significantly elevate my heart rate. The evidence-based health benefits are substantial, covering preventing falls, osteoarthritis, Parkinson’s disease, rehabilitation for chronic obstructive pulmonary disease, improving cognitive capacity in older adults, depression, cardiac and stroke rehabilitation, and dementia (Huston and McFarlane, 2016).

Moreover, weaker evidence finds improvements in psychological well-being including reduced stress, anxiety, mood disturbance, and increased self-esteem (Wang et al. 2010). What explains these benefits? Traditional Chinese medicine says that tai chi works by balancing yin and yang and redistributing qi energy. Psychology offers a different set of explanations, tai chi works through cognitive, emotional and social mechanisms.

Cognitive Effects

The slow movements in tai chi make it look simple but they actually take a lot of concentration. You need to keep track of both arms, both legs, and hips, with novel movements such as forming a hook with a hand. Moving slowly requires more concentration than a faster, jerkier movement. In addition, the movements are accompanied by controlled deep breathing: when hands go up or towards the body, and out when they go down or away from the body. 

Moreover, a short, minute-long sequence in tai chi can require 10 different combinations of movements, each of them with four different movements of hands and feet. A five-minute sequence can require around 200 different actions, not including controlled breathing. Hence, tai chi imposes a large cognitive load on the mind.

This cognitive load prevents my mind from wandering. I’ve tried meditation but never been able to do it for more than 20 seconds because it’s too boring and my mind wanders to more interesting aspects of my life. In contrast, tai chi requires full concentration, reinforced by my teacher who notices if I’m not following precise instructions. Thinking exclusively about body movements prevents people from thinking about other, more stressful aspects of their life such as work, health, and family conflicts. 

How this prevention works is explained by my theory of consciousness. Your brain forms many mental representations that are different patterns of firing in large groups of neurons. These representations compete with each other for the very limited span of consciousness, you can only keep around five to seven things in mind at once. The complex movements of tai chi require new kinds of motor representations that take over consciousness, outcompeting troubling thoughts. I think this is one of the reasons that tai chi reduces stress. 

Emotional Effects

Stress is also a matter of emotions, and tai chi has emotional effects that are more than just cognitive competition. Emotions depend on both cognitive appraisals of how a situation is affecting your goals and on the detection of physiological changes, where appraisals and changes are represented by unified neural representations. Tai chi does not raise heart rate like more vigorous exercise, but the deep breathing definitely impacts physiology in the way that meditation does, producing a calming effect. 

Deep breathing hacks the vagus nerve, which is the longest part of the autonomous nervous system, connecting the heart, lungs, and digestive tract. Calming the body sends signals to the brain that complement the re-appraisal that comes from not being able to think about stressful aspects of life. Tai chi lowers stress by regulating emotions as well as by diverting thoughts.  

Social Effects

I practice tai chi on my own for about 20 minutes on most days, but the classes are group events, as are park gatherings where large numbers of people participate, as I hope to do when I’ve acquired more skill. The sociologist Randall Collins has emphasized the importance of interaction rituals in which mutually focused emotions and attention produce a shared reality that generates solidarity. Interaction rituals are important in religious observances, sports events, dances, and live concerts. Tai chi similarly generates emotional energy from group practices, complementing the individual cognitive and emotional effects on stress reduction. 

©Paul Thagard

Paul Thagard is a philosopher, cognitive scientist, and author of many interdisciplinary books. He is Distinguished Professor Emeritus of Philosophy at the University of Waterloo and a Fellow of the Royal Society of Canada, the Cognitive Science Society, and the Association for Psychological Science. The Canada Council awarded him a Molson Prize (2007) and a Killam Prize (2013). Paul Thagard’s Treatise on Mind and Society was published by Oxford University Press in February, 2019.