“…The famous Okinawan centenarian, Kamada Nakazato, reported that the keys to her long life were to "eat your vegetables, have a positive attitude, be kind to people, and smile" (Buettner, 2010). Quality and duration of sleep have been shown to affect health and reduce mortality (Dew et al, 2003;Kripke, Simons, Garfinkel, & Hammond, 1979) and an optimistic mental state has also been found to be positively related to longevity probably because it assists in relaxation which can reduce multiple mortality factors (Brummett, Helms, Dahlstrom, & Siegler, 2006;Diener & Chan, 2011;Giltay, Geleijnse, Zitman, Hoekstra, & Schouten, 2004). Laughter, is also positively associated with health, through possibly decreasing the risk of heart attack, lowering blood pressure (Hasan & Hasan, 2009;University of Maryland Medical Center, 2005), or minimizing the negative effects of stress by reducing the breakdown of nitric oxide (leading to vasodilatation) and increasing the number of natural disease-fighting killer cells.…”