12 Rules for Life
Stand up straight with your shoulders back
We have the ability to consciously overcome the natural tendency to shrink, slump our shoulders, and limit the release of serotonin. When we stand up straight (literally and figuratively), people around us treat us as someone who has dominance, which in turn helps us believe even more that we are strong and competent. This is a classic example of "fake it till you make it."
When lobsters win a fight, they stand up taller and other lobsters are less likely to challenge them. Now, if a lobster was capable of "pretending" it won a fight, and stood up taller, it could result in the same outcome. This is what we can do.
Treat yourself like someone you are responsible for helping
Similar to the first rule, this rule encourages us to trick our brain into assigning more value to ourselves than we might otherwise. We are all painfully aware of our own flaws, so we have a tendency to neglect ourselves while considering other people (and animals) more worthy of care. The key is to view ourselves from the eyes of someone responsible for helping us, so that we take care of ourselves, and the final result is a better situation for everyone around us.
Another angle that Peterson provides on this rule near the end of the chapter is to make decisions for ourselves not with the goal of achieving happiness or what we want, but with a focus on what is truly best for us in the long run.