The chicken and egg conundrum fades into puny insignificance beside the problem of parents and teenagers. Which exacerbates the other?
Pity the teenagers: their hormones are raging, their bodies are embarrassing them at every turn, they are neither adored children nor irreproachable adults and they need to sleep for 22 hours a day which no-one will let them do.
Or pity the parents: their cherished little darlings have morphed overnight into hulking lumps of sullenness, who flinch at the sight of daylight and from whom their parents are lucky to extract the occasional grunt or uncooperative gesture.
Remember that the one weapon you have over a teenager - and it must be used judiciously and deftly otherwise you will blunt its edge - is embarrassment, an emotion which dogs every teenager, every hour of the day. "Just joining in the fun," is a phrase to chill every teen's blood - try not to use it in front of their friends, merely threaten to use it in front of their friends if they don't co-operate at least one out of ten times.
The good news is that just as you might be feeling flabby and complacent in your chosen career, along comes a teenager to exercise your brain - the negotiating skills you will need when dealing with either your own teenagers or someone else's will make years of study and work experience seem like a warm-up exercise...