Santa

Mainstream: It accounts for the saint's name, the gift-giving and the dated texts and images, such as the 1823 poem and Nast's cartoons, that fix the modern look.

Alternative: It accounts for the resemblance between the red-and-white suit and the mushroom, and between the eight-legged horse Sleipnir and the eight reindeer.

Mainstream: Evidence of a continuous pre-Christian gift-bringer with the chimney, flying team and red suit, with no link to Nicholas, would count against it. Such an unbroken line has not been found.

Alternative: Records of Evenki or Germanic rites that include a gift-bringer entering through a roof opening would support it. No such records are documented, and the red suit appears late, so the suit-to-mushroom link rests on resemblance alone.

Mainstream: It does not explain well why some features, such as the flying team and the midwinter timing, took the form they did. Absorbed pagan customs may be part of the answer.

Alternative: It leans on resemblances and adds assumptions to bridge the gaps. The reindeer count of eight and the red suit come from the 1823 poem and 19th-century art, far later than the supposed ancient source. The Odin link to children's boots is also thin.

Mainstream: It accounts for why Santa was already jolly and red-suited in 19th-century art and in earlier department-store ads before Coca-Cola's 1930s campaign.

Alternative: It accounts for the uniform look worldwide and for the link between Santa and retail seasons.

Mainstream: Pre-1930s images of a plump, red-clad Santa would count against a purely corporate origin, and many exist.

Alternative: Pre-Coca-Cola red Santas would count against it, and these have been observed.

Mainstream: It cannot say how much commerce standardized the figure compared with the way earlier publications shaped it, since the two overlap.

Alternative: Sundblom's 1930s work was built on much older images, so the claim that Coca-Cola created the look is easy to overstate. The commercial-function claim does not need the 'creation' version.

Mainstream: It accounts for the fact that most adults remember Santa fondly and show no lasting harm.

Alternative: It accounts for children's detective-style testing of the story, such as checking the logistics or finding hidden gifts.

Mainstream: Lasting loss of trust in parents, or no gain in behavior, would count against it. Research is mixed, and some people report upset when they learned the truth.

Alternative: Studies showing that children who believe in Santa and then debunk him reason no better than others would count against it. Little direct evidence exists either way.

Mainstream: The 'naughty or nice' behavior claim is thinly tested. Some adults report distress on learning the truth, which the 'harmless' claim passes over.

Alternative: The claim presumes that adults deliberately design the myth as a puzzle, but parents rarely do. Whether debunking transfers to later skepticism has not been shown.