For example, nothing is extremes of thoughtfulness with such types (7)

'such types' is the definition.
The definition and answer can be both people as well as being plural nouns.
Maybe there's an association between them I don't understand?

'for example nothing is extremes of thoughtfulness' is the wordplay.
'for example' becomes 'e.g.' (short for 'exempli gratia', 'for example' in Latin).
'nothing' becomes 'O' (looks like zero - 0).
'extremes of' means to remove the middle letters (only the letters at the extremes of the word).
'thoughtfulness' with its centre taken out is 'ts'.
'eg'+'o'+'is'+'ts'='EGOISTS'

'with' is the link.

Can you help me to learn more?