http://www.curiousapes.com/the-science-of-happiness-why-complaining-is-literally-killing-you/

The basic premises of this essay are far more powerful than the author asserts. Effectively he is saying that every action or thought stages something similar, inclines us to repeat or deepen that habit, and even over relatively short periods of time, we can lose or establish astonishing faculties and abililties… simply by ‘habituating’ to orientations that either stage development, inhibit it, or directly assault existing faculties and abilities.