"Incontent" is not a well-known term in the context you provided. It could potentially refer to content that is included within something else, such as text within a document or body of a webpage. If you have a specific context in mind, please provide more information for a more accurate answer.
While it might be considered abnormal or odd if you will to many I assure you that a teenager cannot become incontinent by just sleeping in a crib. There is more too it than just the choice of bed.
The effects of not having friends depends very strongly on the individual. That means, if you yourself think you need friends, then not having any will hurt you very much and turn you into an unhappy, incontent person. However if you don't see them as necessary, you can be fully content with your life without friends. Biologically however social interaction is natural for humans which is why through instincts we look for other people's company.