Researchers have discovered that divorce is so contagious among friends we're 75 per cent more likely to end our marriage if someone we know is splitting up.
Apparently, 'divorce clustering' happens when one person in a social group breaks up, causing everybody around them to start questioning their own relationships. This sets in motion a kind of domino effect of doubt.
But haven't we always driven our friendships under the influence of a little one too many comparisons? Coffee mornings being a classic, loosely disguised opportunity to see who manages to clear up breakfast and prise the cereal off the kitchen floor before the school run.
And when friends make decisions on what car to drive or what shade of Farrow and Ball sludge green to decorate in, don't we all rush home, shut the front door, and wonder if our own lives could do with a lick of paint?
Take a typical conversation in my house.
Me: 'The Whatsits have decided that, as a family, they're only drinking soya milk from now on.'
Husband: 'Sounds disgusting.'
Me: 'Apparently it's full of vegetable proteins and reduces toxic substances in your body.'
Husband: 'So does doing a poo.'
Me: 'But we should be healthier too. They do loads of exercise at the weekends. And their kids eat olives. Last week, I even saw a packet of lentils soaking in their fridge..'
And so it goes on. But for many, the decisions a friend makes can have a hugely negative impact. Sharon Wills, 42, is the mother of Izzie, nine. 'I don't like to think I'm the kind of person who can be swayed by what my friends do, but recently another mother I'm close to pulled her daughter out of our local school.
She's someone whose judgement I've always trusted and her decision to leave had this weird, knock-on effect in the playground. Suddenly everybody was voicing concerns about class numbers and reading levels and trying to second guess what, exactly, had caused the child to be moved. It was as if, overnight, our trust in what we knew was shaken. As a group of mothers we went from feeling pleased with the school to questioning everything about it. And within a month another two children had left.'
For my part, it's when a friend moves home that I start suffering from symptoms. Suddenly everything in my own house looks tired and worn. No matter that we've only lived here one year. Why, oh why, couldn't we have somewhere with a bigger hall and separate utility room? It's not long before I've succumbed completely and can be found loitering outside estate agents windows furiously calculating stamp duty. There's no hope. Except, like all contagious diseases, experts recommend solitary confinement. Now there's something to be envious about....
More contagious behaviour:
1. Recycling. Nothing like a friend purchasing a water butt to nudge our social conscience.
2. Buying a new fridge. It makes ice?? Say no more.
3. Holiday destinations. Why do we meet everybody we know on the Portsmouth – St. Malo Brittany ferry?
4. Boden. We just can't help ourselves.
5. Ditto Crocs.
6. Feeling tired. It just takes one person to yawn...
7. Braving that moment when we go from wearing winter tights to baring legs. Go on – you go first.
8. Moaning about husbands and children
9. Labradoodle puppies. Such a stupid name but everyone's caught on to the fact they don't shed..
10. Facebook. The technical way to catch stuff off friends.
Do you suffer from envy obsessions?