Damage to the brain’s right frontal lobe makes some people tell inappropriate jokes. Have you known someone with this condition? It’s very interesting to me what a malfunction in a certain brain area can do to a person’s behavior.
Witzelsucht (German: “joking addiction”) is a set of pure and rare neurological symptoms characterized by a tendency to make puns, or tell inappropriate jokes or pointless stories in socially inappropriate situations. It makes one unable to read sarcasm. A less common symptom is hypersexuality, the tendency to make sexual comments at inappropriate times or situations. Patients do not understand that their behavior is abnormal, therefore are nonresponsive to others’ reactions. This disorder is most commonly seen in patients with frontal lobe damage, particularly right frontal lobe tumors or trauma. The disorder remains named in accordance with its reviewed definition by German neurologist Hermann Oppenheim; its first description as the less focused moria [pl] (pathologic giddiness or lunatic mood) by German neurologist Moritz Jastrowitz, was in 1888.
— Read on en.m.wikipedia.org/wiki/Witzelsucht