Happiness is a mental or emotional state of well-being characterized by positive or pleasant emotions ranging from contentment to intense joy. A variety of biological, psychological, religious, and philosophical approaches have striven to define happiness and identify its sources. Various research groups, including positive psychology, endeavor to apply the scientific method to answer questions about what "happiness" is, and how it might be attained.It is of such fundamental importance to the human condition that "life, liberty and the pursuit of happiness" were deemed to be unalienable rights by the United States Declaration of Independence.The United Nations declared 20 March the International Day of Happiness to recognise the relevance of happiness and wellbeing as universal goals. In 2014, Happy became the anthem and inspired clips from around the world.