From that BBC link:
Much has been made of the fact these are the groups going out socialising, although it is also noticeable that the highest rates are spread across much of the working age population - many of whom will have to leave their home to make a living.
Though I agree with Blobby10 point as well - I met, like quite a few friends DH at university, but we weren't living togther till late 20s mainly as we were in different cities due to jobs./carrers. So they are an age group less likely to be settled.
My IL retired are actually doing more soliaising than us - they were also slower to stop and quicker to start back up but then I've noticed quiet a few people saying older family members- like my own parents- who stopped everything have aged very badly physically and mentally.