Those back to front types have a characteristic spirit (5)
I believe the answer is:
ethos
'a characteristic spirit' is the definition.
(I've seen this before)
'those back to front types' is the wordplay.
'back' suggests the final letters.
'front' says to take the initial letters.
'types' becomes 'hos' (I can't explain this - if you can you should give a lot more credence to this answer).
The final letter of 'those' is 'e'.
The initial letter of 'to' is 't'.
'e'+'t'+'hos'='ETHOS'
'have' acts as a link.
Can you help me to learn more?
(Other definitions for ethos that I've seen before include "Characteristic spirit of a culture or era" , "Culture, way of life" , "Characteristic spirit, of a culture say" , "General feeling" , "Distinctive spirit of an institution" .)