If one studies the causes and conditions that lead to happiness then puts them into practice, he or she will be happier. Happiness is learned. This is supported by modern science and many contemplative and wisdom traditions.
I discuss this in detail here The Learned Happiness Model (LHM)
The Happiness PhD Project (Encyclopedia)
1A1. Neuroscience research shows happiness is learned: wellbeing is a skill.
1A2. Learned helplessness is the psychological theory describing how we “give up”.