What is the psychological function of nostalgically reenacting activities from before we were born? I'm asking specifically about nostalgia for a time before you were born, e.g. the Blitz parties / 40s tea dances that have big in the UK for the past decade, or the popularity of Speakeasy-themed bars in the US. I'm thinking of nights that require you to dress in theme specifically and celebrate that time.

I was discussing it with a friend today, and I said it seems like it's a way to participate in something your grandparents did that strengthens your bonds to your own family, but she (rightly) replied that her own grandma had never been to a dance – she'd been too poor. It seems to me like when we're at the tea dance or in the speakeasy or whatever, we're doing something more than faithfully reenacting the things our forebears did, but I'm not sure what that is or why. Are we celebrating the best bits and leaving the rest behind? Are we thoughtlessly celebrating a time of awful gender and racial inequality? Does anyone have any insight into this kind of nostalgia, the nostalgia for things you've never experienced yourself, and the act of participating in themed events, and what functions that has socially/psychologically?
Historic reenactment and historically themed social events may serve a variety of functions for the different people that participate in different events:


Some people in virtually all societies value traditionalism (Schwartz, 1992).

Traditionalism relates to religiosity (among Judeo-Christian faiths; Schwartz &amp; Huismans, 1995).

Some hold romantic ideals of the past (e.g., the notion of "simpler times"). Personality traits related to these attitudes may (I'm speculating here) include the past-positive type of time perspective (Zimbardo &amp; Boyd, 1999) and low openness to experience, which also relates to traditionalism.
Some may desire an escape from the ordinary environments they're used to in daily life.
Some enjoy dated fashions that don't seem quite right to wear in ordinary, modern contexts.
Some events involve celebration of history, which is valuable in its own right.
Some attendees probably enjoy any opportunity to dress up, act a part, or socialize in general.

Extraversion and self-monitoring may be relevant traits for understanding these motives.
The motive itself may be the need for affiliation, which is stronger in some individuals.
Social contact serves many psychological functions, including the enhancement of well-being.



Surely some celebrants are ignorant of the social issues of those times, but some aren't. Either way, many choose to celebrate the times for their good aspects, and at least a few probably feel the good aspects include the less modern social views of those times. It's conceivable that some people would even feel more comfortable in situations where attitudes such as misogyny or racism could be expressed more freely by excusing them as part of an act. However, my mere intuition and very limited personal experience suggest that most celebrations of the past aren't celebrations of the more controversial aspects such as these.

References

Schwartz, S. H. (1992). Universals in the content and structure of values: Theoretical advances and empirical tests in 20 countries. Advances in Experimental Social Psychology, 25(1), 1–65. Retrieved from http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.220.3674&amp;rep=rep1&amp;type=pdf.

Schwartz, S. H., &amp; Huismans, S. (1995). Value priorities and religiosity in four Western religions. Social Psychology Quarterly, 58(2), 88–107.

Zimbardo, P., &amp; Boyd, J. (1999). Putting time in perspective: A valid, reliable individual-difference metric. The Journal of Personality and Social Psychology, 77, 1271–1288.