Self-compassion has received a lot of research recently (over 1,000 published studies)! Psychologist Dr. Kristen Neff was the first to come up with a formal definition of self-compassion, and use it as a measure in psychological research. Her definition of self-compassion is made up of 3 components.
1.) Mindfulness
In order to give ourselves compassion we must first be aware that we are suffering. Mindfulness simply means opening up and acknowledging our pain. In other words, noticing your thoughts and feelings. For example, you might say to yourself I am having the thought that I am not good enough, or I am having the thought that I am a lousy parent. You could also take note about what feelings these thoughts bring up, for example I notice a feeling of guilt, shame, sadness, worry, etc. For more information on mindfulness, check out my blog post on the topic.
2.) Common Humanity
When we suffer it is common to experience a sense of isolation. Common humanity involves reminding ourselves that as humans we all suffer, we all fail, and we are all inadequate in some way. If you are having a certain thought or feeling it means that millions of other people around the world have also had that same thought or feeling. This part is not intended to minimize your pain, or imply that things are not that bad. Instead, the purpose is to remind yourself that you are not alone. There is a great quote that sums this up nicely.
“You are not one drop in the ocean, you are the entire ocean in one drop”
Rumi
In other words your pain is part of the wider human experience. It does not isolate you, in fact it unites you with everyone else.
3.) Self-Kindness
This can be the trickiest part of self-compassion for many people. Self-kindness means speaking to yourself the same way you would speak to someone you deeply cared about. Quite often, our minds are our own worst enemies. When we are struggling with something, our minds tend to beat us up. However, if someone we loved was struggling with the exact same thing, we usually would respond with kindness. Take a moment to think about the last time someone you loved was going through something difficult… what did you say to them? How did you act towards them? Now, think about the last time you were going through something difficult… what did you say to yourself? How did you act towards yourself? For many of us there is a drastic difference.
But does it actually help?
There is a growing body of research that shows self-compassion can protect us from developing mental health issues. One study really stood out to me. Hiraoka et al. (2015) measured levels of self-compassion in U.S. combat veterans coming back from Iraq and Afghanistan. They found that those with higher levels of self-compassion were less likely to develop symptoms of Post-Traumatic Stress Disorder (PTSD) one year later, and that this was more predictive than the amount or quality of the combat they faced. Think about that for a second, how these veterans related to themselves in their moments of pain and struggle was more predictive of whether or not they would later develop PTSD than the actual trauma they faced.
We all have different levels of self-compassion. But what is very exciting, is that research has shown self-compassion is something that can be learned, and when taught, can increase emotional resilience in the face of stress and lead to greater overall psychological well being. There are many different types of self-compassion practices you can implement into your daily life. Below I have attached an excellent workbook that does just that, as well as Dr. Kristen Neff’s website where you can measure your current level of self-compassion, access free self-compassion exercises, and also learn the common misconceptions people have about self-compassion.
Resources

Dr. Neff’s Self-Compassion Website
References
Hiraoka, R., Meyer, E. C., Kimbrel, N. A., DeBeer, B. B., Gulliver, S. B., & Morissette, S. B. (2015). Self‐compassion as a prospective predictor of PTSD symptom severity among trauma‐exposed US Iraq and Afghanistan war veterans. Journal of Traumatic Stress, 28(2), 127-133.