The research that has been done on this topic suggests that everyone basically has a happiness set point, sort of like a thermostat that is set at a particular temperature. That set point is determined by our DNA/ancestry.

While our set point is determined by our DNA, we can all move beyond it by the choices we make in our lives.

For example, financial, material and career success will cause our happiness levels to rise, as will doing such things as practicing religion/spirituality, exercising, socializing with friends and family, practicing gratitude, engaging in "flow activities" (e.g. hobbies that we greatly enjoy), entering into marriage, etc, etc.

All these activities will increase our happiness, but the rise is only temporary, because at some point we all will return to our genetically determined happiness set point.