Group-think - have you ever succumbed to it? I know I have.
You share experiences and interests with the rest of a group, you reinforce each other's assumptions and beliefs, you embrace the apparent consensus - and then you're taken aback when you discuss it with outsiders who turn out to have a very different perspective on the issue involved.
It's not an unknown phenomemon in the BBC. Nor is it in the House of Commons.
Last week, when I heard MPs talk about the need to amend the FOI law to put themselves outside it, I was struck by the disparity between how they regarded their own concerns about their position and how their action would be regarded by the general public - and by their apparent ignorance of the size of this disparity. Perhaps not so much group-think as Commons-think or possibly common-think.
Anyway the Labour and Tory leaderships have clearly realised, if somewhat belatedly, the damage to the reputation of Parliament caused by the passing of the Maclean Bill, whatever their view of the merits of it. Those words 'compromise' and 'climbdown' are in the air.
The Bill will clearly not pass the Lords in its current form, if it passes at all.
Clause 1(2) in the Bill exempts all information held by Parliament from the FOI Act. Clause 1(3) exempts MPs' correspondence held by other public authorities. These two proposals are completely separate. If the Bill had only included the latter in the first place, and not the former, then (leaving the other arguments aside) it would have been much better for the public standing of the British political class.
But, whatever happens with this Bill, it's also worth reviewing the state of current ministerial thinking on the government's plans to restrict FOI generally. These will have much more impact in curtailing FOI than the Maclean Bill.
Currently public bodies can turn down FOI requests if it would take too long to find the information. The government wants to allow them also to take into account the cost of reading it and considering and consulting others on whether to disclose.
Ministers are still keen on this plan, even though they are now also consulting the public on whether any change to the FOI rules is necessary at all. They argue that these costs exist and so in principle should be reflected. They understand the counter-arguments - that in practice their plan will prevent valuable disclosures, while being open to abuse, providing perverse incentives to inefficiency, and prompting an increase in appeals which would reduce the cost savings. They look to the Information Commissioner to deal with such problems.
The other government proposal last December was to allow public bodies to 'aggregate' all the requests received from one organisation within three months in working out whether the cost limit is exceeded, even if they are completly unconnected. However ministers have clearly taken on board the criticisms of this idea.
In March Lord Falconer stated that if requests 'are genuinely different then aggregation should not apply'. The ministerial viewpoint is that aggregating requests is purely to stop requesters getting round the cost limit by splitting up one request into several different ones, and that authorities should not be allowed to aggregate unrelated requests. The government is naturally reluctant to present this as a climbdown. But it is clear that Falconer's remarks in March are now the government's official position, and that this is different from the proposal in the government consultation last December.
So at the moment we can still expect the goverment to proceed with a part of its plans to restrict FOI. But of course such a decision may well be perceived in a very different way inside ('necessary reduction of an excessive administrative burden') and outside ('outrageous obsession with secrecy') official circles. And it may well be a different group of ministers taking the final decision, chosen by Gordon Brown. Will they worry about being trapped by group-think?
Meanwhile I'm going to a freedom of information conference tomorrow, with hundreds of other people who will happily spend all day discussing FOI, because it's one of the most fascinating and important topics facing the country today. But then everyone thinks that, don't they?