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Comment by ealloc | Hacker News Reader

This is definitely a "Just So" scientific story. That is, it is an unverifiable account of why things might have happened. They used to be common in evolutionary thought until it became clear they were often wrong.

Just so stories can be thought provoking, but I'd prefer it if people writing them made it clear what they are, since they can often lead to muddled ideas rather than clarity. The tone of this article bugged me a little.

I've also heard this story before, and if you google you will see there are many alternative explanations, for example that red paint was chosen because it is a fungicide rather than because it was most plentiful. Why add any pigment at all, if cost is the issue?

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This didn't seem like an egregious example, because I didn't sense it was meant to be taken all that seriously. "Just So" stories are alive and well in evolutionary psychology. How could you verify that X behavior came about because it helped humans get away from tigers in Africa 20 million years ago? It sounds plausible, I guess, if you take for granted that it must be explicitly coded for somewhere in the genome. But I don't.

Why add pigment. Every stood next to a white wall in bright sunshine? There's also the aesthetic reasons, people don't just optimize for cost, they like things they live with to look a certain way.

The likely reason is a bunch of reasons, including human nature, herd mentality, or what we today call going viral. Possibly it was just a really good paint salesman that had a load of spare red going cheap.

The tone didn't bug me in the slightest, it took it for what it was, a bit of fluff writing that had a pretty photo to look at.

Herd mentality is very likely.

Many barns in USA are red. Most barns in USSR were not painted at all. Most French barns don't appear to be red either: http://www.google.com/search?q=image+barn+france

Your looking at stone barns in France, wooden barns and wooden doors on stone barns are often red.

I was under the impression that it was red because it was best color for keeping the heat absorption even.

Unpigmented "paint" is not white, it is usually* clear-ish. Titanium dioxide is the usual white pigment.

On the topic of why iron oxide pigments are used rather than keeping paint clear: they protect the surface from UV light.

* There are multitudes of paint bases, all the ones I can recollect are transparent with a yellow/brown tinge. One exception is acrylic emulsion paint base, which looks white but dries clear, unless a pigment is added.

Here's another explanation, which I think is much better.

http://www.farmersalmanac.com/blog/2008/09/16/farmers-almana...

Indeed. I feel dumber for having wasted time of this clickbait.

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