Keeps performing - it does have an effect (4,2)

'keeps' is the definition.
The answer and definition can be both to do with social activities as well as being verbs in their -s form.
Perhaps there's an association between them I don't understand?

'performing it does have an effect' is the wordplay.
I cannot quite understand how this works, but
'performing' could be 'on' (as in being on stage) and 'on' is found in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
'an' could be 'a' and 'a' is present in the answer.
This explanation may well be incorrect...

Can you help me to learn more?