As a teenager, some of my friends became quite chummy with my parents. But usually teenage children want their parents to stay quiet. Why might a parent wish to talk to other teenagers?
1. The parent seeks to estimate the quality, or at least the politeness, of the child’s friends.
2. The parent wishes to feel connected to younger generations.
3. The parent is nervous and wishes to relieve the tension of quiet. And not speaking is seen as an abdication of parental responsibility.
4. The parent wishes to establish the authority to do something the child does not like.
5. The parent finds those children genuinely interesting.
6. The parent wishes to pretend a reasonable relationship with the peers of their child, either to feel involved or to pretend that everything will be OK.
None of these motives are popular with the sons and daughters of the conversing parent. If a put on my technocratic Paretian hat, this is sooner an activity to be taxed than subsidized.