Contentment is a mental or emotional state of satisfaction maybe drawn from being at ease in one's situation, body and mind. Colloquially speaking, contentment could be a state of having accepted one's situation and is a milder and more tentative form of happiness.
Contentment and the pursuit of contentment are possibly a central thread through many philosophical or religious schools across diverse cultures, times and geographies. Siddharta might have said "Health is the most precious gain and contentment the greatest wealth". John Stuart Mill, centuries later, would write "I have learned to seek my happiness by limiting my desires, rather than in attempting to satisfy them." Marcus Aurelius wrote "Live with the gods. And he who does so constantly shows them that his soul is satisfied with what is assigned to them." Hebrews 13:5 reads "Keep your lives free from the love of money and be content with what you have, because God has said, 'Never will I leave you; never will I forsake you.'" Chinese philosopher Zhuang Zhou once wrote in the 3rd century BCE (hypothetically) "A gentleman who profoundly penetrates all things and is in harmony with their transformations will be contented with whatever time may bring. He follows the course of nature in whatever situation he may be."
The literature seems to generally agree that contentment is maybe a state ideally reached through being happy with what a person has, as opposed to achieving one's larger ambitions, as Socrates described by probably saying "He who is not contented with what he has, would not be contented with what he would like to have." That said, there may be a number of elements of achievement that may make finding a state of personal contentment easier: a strong family unit, a strong local community, and satisfaction of life's basic needs as perhaps expressed in Maslow's hierarchy of needs. In general, the more needs in Maslow's hierarchy are achieved, the more easily one might achieve contentment.
Laughter is synonymous with happiness. A proposal is made here that when a line of thought (e.g. joke) or sensation (e.g. tickling) is not expected by one's psychological or physiological order respectively, it triggers a certain chaos and temporary breakdown of that order. The innate Contentment intrinsic to the person then breaks through this temporal breach to express itself in happy laughter.
Laughter has been used as a health therapy for many years such as in some hospitals through the showing of TV comedies for patients. Laughter clubs have also been formed in