Laughter is good for us. In addition to contributing to happiness and life satisfaction, regular doses can help boost the immune system by lowering blood pressure; helping facilitation digestion; increasing alertness, memory retention, and blood circulation; easing muscle tension; relieving stress; and helping combat depression.
A sense of humor and havin 'a laugh can take the edge off everyday stressful situations and life's challenges. Enjoying jokes, and telling them, are common human activities. Humor contributions to healthy aging: oldies (60+ years) tend to use humor as a coping mechanism.
Studies show that oldies enjoys humor even more than younger people. The downside is that the actual amount of laughter declines with age. Oldies seem to experience increasing difficulties understanding jokes: humor appreciation increases with age but comprehension decreases. At around 60 years of age, the amount of laughter exhibited is smaller compared to young adults.
Most of the decline in laughter tends to occur in the evening, when oldies tend to laugh only half as much as their younger counterparts. Two main reasons could help explain this decline in laughter in the evenings. One reason could be that the decline is due to a lack of social interaction at that time; given that most laughter occurs in the presence of, and interacting with, others. Another reason could be that oldies tend to go to bed / sleep earlier than younger adults, giving them (oldies) less time to laugh.
By the way, if you're telling a joke to an oldie keep in mind that most of them do not enjoy aggressive types of humor (sarcasm, making fun of others, put-downs, snide remarks, insults) and are especially sensitive to jokes referring to old age. Focus on the philosophical question: are oldies laughing because they're happy or are they happy because they're laughing?