In my opinion, the evolution of humanity is held back because people are afraid to touch each other due to fear of rape.

EXPANDING: rape, also homosexuality and other perceived sexual violations;
DELIMITATING: perceived, or possible, as opposed to actual;
EXPANDING: physical taboo, also emotional and intellectual — fear of crossing personal boundries.
REVISING: telepathy is neither a feasible solution to imperfect communication nor essential to understanding.
OBVIATING:
safety is contrived to secure those boundries communicatees
maintain; one of society's functions is to establish a common sense of
boundries so that "safe" communication is possible.  Communicators
are not able to ascertain communicatees' boundries in real time without
telepathy.
EXPANDING: global sense of boundries
varies continuously, if this sense is allowed to become too restrictive
social collapse is imminent.  Diminishment of this sense is
entirely the responsibility of the communicatees, and, slowly, the
communicators will accomodate.