It can be inferred from the passage that______.

It’s not that people are either mentally strong or mentally weak. We all possess some degree of mental strength, but there’s always room for improvement. Developing mental strength is about improving your ability to regulate your emotions, manage your thoughts, and behave in a positive manner, despite your circumstances.
   Just as there are those among us who are predisposed to develop physical strength more easily than others, mental strength seems to come more naturally to some people. There are several factors at play to determine the ease at which you develop mental strength.
   Genes play a role in whether or not you may be more prone to mental health issues, such as mood disorders. Some people have personality traits that help them think more realistically and behave more positively by nature. Your life experiences influence how you think about yourself, other people, and the world in general.
   Obviously, you can’t change some of these factors. You can’t erase a bad childhood. You can’t help it if you are genetically predisposed to ADHD. But that doesn’t mean you can’t increase your mental strength. Anyone has the power to increase mental strength by devoting time and energy on the self-improvement exercises.