Stupid or inane behavior is imbecility. Picture a frat party gone wild, and you can picture imbecility.
Foolishness that would be typical of an imbecile is imbecility. Imbecility is from the Latin imbecillitatem, meaning “weakness, feebleness.” If you are feeble of mind or weak on intellect and act accordingly, that is imbecility. For instance, you may have witnessed a college party that was so rife with imbecility that you were amazed that the participants were students in an institution of higher education.