Figgie, I am curious, in a situation like that where the spouse is expected to do more than just 'not be a social embarrassment', what happens with single employees? Is it just expected everyone in the company is married? I know you say it's conservative, is that what's meant? I have honestly never experienced anything like that, so it's totally out of my frame of reference. It seems really stressful, in any case!
The company doesn't expect all of its employees to be married. It does expect those who move to the upper tier to be in a supportive re*la*tionship (marriage equivalent) because at those levels, the demands for time and travel that they place on their employees means it is difficult to do what the job requires without someone else managing all of the rest of the details of your life.
It is hugely stressful, especially during the interview process. As the spouse, I have to be able to figure out what the people doing the interview want from a wife and then give whatever impression it is that they want so that I don't sink my spouse's chances. I need to be able to get along with everyone and I also need to know how to order and eat in the restaurants and even which fork to use.
Generally (but not always) the spousal part of the interview has taken place at a restaurant.
Everyone at my spouse's level and above is married. All of them but one to their first spouse. While I don't know for sure that that is a criteria when they advance/hire people, I suspect that it might be because of the prevalence of people at that level who have been married a good number of years to only one spouse.
And to bring it back to the original question...it would kill someone's chances of advancement to come to a Christmas party (which is really just another work function) with someone other than a person that they are in a spouse type re*la*tionship. Since one of the functions of the party is to assess how well people are working together and to see which people are ready to move up and which aren't, it is important for the higher ups to see the couples together.