# Once intelligent beings achieve technology and the capacity for self-destruction, the… by Carl Sagan > "Once intelligent beings achieve technology and the capacity for self-destruction, the selective advantage of intelligence becomes more uncertain." > **— Carl Sagan**, *Broca's Brain / intelligence discussion, source verification pending* Verification Status: Unverified — exact wording/source has not yet been independently confirmed against a primary source; source clue: Broca's Brain / intelligence discussion, source verification pending.