The viral '30 seconds or less' rule of kindness: Does it help mental health?

A few days ago, a US school teacher's video on a '30 seconds or less' rule on kindness captured the attention of netizens. In the video, Natalie Ringold, a fourth-grade teacher, explains to her students that if someone can't change something about themselves in 30 seconds or less, it shouldn't be mentioned to them. Quoting examples like 'Hey your shoes are untied,' or 'Or you have a little fuzzy on your shirt,' she said, "If you say something like that to someone, they can change it in less than 30 seconds. But if you comment on someone's hair colour, texture or style or body, they can't change it in 30 seconds." The teacher, who is getting widely appreciated for her advice, added, "Your words have power. If at all you apologise and try to take the words back or undo it, it's not possible." Lapping up her words, many went on to add famous observations on kindness, including Mother Teresa's 'Kind words can be short and easy to speak, but their echoes are truly endless.' Psychologists have also explained time and again that exercising kindness in this manner can have many mental health benefits, which are:

1) Reduces cortisol, triggers dopamine
It triggers the dopamine in your brain. Renowned American psychologist Martin Seligman once said that practising kindness can improve our mood by forming a positive feedback loop in our heads. It can also trigger a relaxation response in our brain, reducing the stress hormone cortisol. 
2) Improves emotional intelligence
Practising kindness can help improve interpersonal skills. It can also help build the emotional resources required to handle tougher situations like bullying. According to spiritual leader and Nobel Prize winner Dalai Lama, it is also the key to developing emotional intelligence and tact. 'Kindness, compassion and tolerance are not signs of weaknesses, they signify strength,' he once said. 
3) Habit creation
Once you cultivate the 30-second rule of kindness as a habit, it can have a lasting impact on your mental health. Start small with a deliberate action of kindness and practice gratitude to further inspire you to do more of it. If you feel up to it, you can also challenge yourself at times to engage in bigger acts of kindness. Over time, you will notice it boosting your emotional resilience and self-esteem and maybe, even cause a ripple effect inspiring others.