First, the good news. We middle-aged Brits are no longer condemned to the conversation- and soul-destroying monomania of debating house prices.

Less good is what has displaced it – an epidemic of angst about when to allow teenagers a mobile, and what kind. I’m in the “very late and a brick” camp, but parents end up discussing the options for a smartphone-free childhood, inevitably, on WhatsApp.

There’s lots we don’t know about the effects of smartphones but what we do know is not encouraging. The significant rise in teenage mental health problems coincides with the spread of smartphones and social media.

The rollout of Facebook in US universities in the 2000s had a negative impact on students’ mental health and a new Chinese study revealed that for parents who focus on academic outcomes, the evidence is building of the effects of addictive apps on grades.

Researchers looked into phone data with university records on grades and post-graduation employment, tracking three cohorts of students for up to four years. Being a high user of apps was bad: it significantly reduced students’ grades (and physical health) but also their subsequent wages – reducing pay by 2.3%.

Added to this is a new worry: the roommate. Not only because someone furiously tapping away is distracting, but also because phone/app use is contagious. The paper found that if your roommate increases app use, you suffer around half the negative effects that they do.

You never know, our new preoccupation might actually do more good than all that chat about the housing market.

• Torsten Bell is Labour MP for Swansea West and author of Great Britain? How We Get Our Future Back