It is a very sensitive topic as some people try very hard to show that they have a great sense of humor but most of them fails miserably. As it is not at all an easy task to make someone laugh on your joke. Good sense of humor is not very common. There are many levels ofgood humor and that helps people to develop their social circle. One can see it as a well known computer science problem of clustering.Same kinds of people cluster together to make a group.