Simply put, dick jokes get the quickest and biggest laughs, and in stand-up comedy, size does matter.
[4]However, due to their prurient nature, comedians who rely on explicit humor must find less controversial subject matter if they wish to expand their presence to more restrictive venues like network television and family films.
In short, "young professionals whose success has been achieved on the stepladder of dick jokes must eventually change their acts".
[5] An example of a joke of this type relying on an unspoken connotation is: [A] particularly beautiful student was stunned when the biology professor asked her, "What part of the human anatomy enlarges to about ten times its normal measurement during periods of emotion or excitement?"
I refuse to answer that question", the girl stammered as she shyly avoided looking at her male classmates sitting nearby.