All cultures, as far as I know, have festivals and special celebratory days. At least they are extremely widespread — harvest festivals, for example. I believe they have a genetic basis. The underlying genes evolved because they increased sales of high-end “useless” stuff. This helped skilled artisans — a big source of technological innovation — make a living. Economists speak of the “deadweight loss” of Christmas because people buy stuff that would otherwise not be bought.
China retail giant Taobao (like Ebay, except better) has shown a shrewd understanding of the festival/shopping link. On Chinese campuses since the 1970s there has been a joke holiday called Singles Day (11-11). For people who are not in a relationship. In 2010 Taobao started having a sitewide sale on that day. This year total sales were $500 million. One retailer, one day. (For comparison, all US online retail sales for the 2010 holiday season were $33 billion.) No crowds, no difficulty parking, no long lines. Still stressful, yes, but in a good way: “This is so exciting – a war and a carnival at the same time,” said one shopper.
This is why it’s so easy to not take evolutionary psychology seriously, because most often amateurs, but in this case, even people with psychology degrees, can and do simply make up stories and declare them genetic in basis.
You say “The underlying genes evolved because they increased sales of high-end “useless” stuff. This helped skilled artisans” but stop! The underlying genes became human-universal so that they could help a small cadre of people? No way! This is group-evolution theory at its subtlest! An evolutionary psychology argument that has even the slightest bit of probability needs to not just be a Just So Story, but to propose a mechanism by which individuals with the genes in question benefitted over individuals without. Harvest festivals require massive participation to be beneficial, and would seem to benefit everyone once they exist. There is no mechanism (proposed or immediately obvious) by which this could influence the relative frequency of an allele.
Wishful thinking is a common failure of amateur evolutionary psychologists, and it does a lot of damage to the credibility of the field as a whole. It takes very very careful analysis to discover a genetic basis to human behavior because of the massive adaptability of human behavior.
This is why it’s so easy to not take evolutionary psychology seriously, because most often amateurs, but in this case, even people with psychology degrees, can and do simply make up stories and declare them genetic in basis.
I suggest you read my paper and see if I “simply made up a story”. That paper will also help you judge how plausible my explanation is. If you have another plausible explanation of the ubiquity of harvest festivals and the like, I would like to hear it.
propose a mechanism by which individuals with the genes in question benefited over individuals without.
Groups with the genes innovated more than groups without the genes. The more innovative groups competed successfully against less innovative groups. I am sure you are aware of group-vs-group competition, even if critics of “group selection” have had trouble with the concept.