Aims to take behaviour towards the extreme? (7)
I believe the answer is:
endways
'towards the extreme?' is the definition.
I can't tell whether this definition defines the answer.
'aims to take behaviour' is the wordplay.
'aims' becomes 'ends' (I've seen this before).
'to take' is an insertion indicator.
'behaviour' becomes 'way' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ends' enclosing 'way' is 'ENDWAYS'.
Can you help me to learn more?
(Other definitions for endways that I've seen before include "Lengthwise" , "as a departing bus is seen" , "Turned up" , "Not sideways/lengthways" , "Not side on" .)