Personalities say nothing succeeded (4)
I believe the answer is:
egos
'personalities' is the definition.
(I've seen this in another clue)
'say nothing succeeded' is the wordplay.
'say' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'nothing' becomes 'O' (looks like zero - 0).
'succeeded' becomes 's' (genealogical abbreviation).
'eg'+'o'+'s'='EGOS'
(Other definitions for egos that I've seen before include "Lots of self-esteem" , "Self-images" , "People's personal pride - the parts of them that are conscious" , "feelings of self-importance" .)