The Feathers Make the Bird

I’m not one for fancy clothes; if anything, I’m fond of the children’s story, The Wise Shoemaker of Studena, about a wise cobbler who was invited to a wedding and who soon realized he had been invited for the externals he represented, and not his true identity. I own 8 plain white shirts and a few pairs of gray and black slacks, and a bunch of ties I know match with them, and that set-up takes me through the week.

That said, I know perfectly well that clothes affect our mood; I once taught a semester-long adult education course, “Jews and Clothes,” and this was a recurring theme. We are supposed to have special clothes for davening (nice or less nice, depending on the circumstances of our prayer), and clothes of honor for Shabbat and Yom Tov. The colors of our clothes, as I noted here (under "7a"), are special as well.

The Kohanim wore special uniforms to serve in the Beit haMikdash, and they were required to keep that clothing clean and to wear only clothing that fit perfectly. Jews wear special clothing to signify mourning. We recite a special berachah to mark the joy of new clothing and transform it into religious celebration.

In some sense, we recognize that clothing not only reflects a mood or special occasion, but actually generates that mood or special occasion. You are, indeed, what you wear.

And into the mix comes an article from Science Daily on the way the colors of birds’ feathers, when artificially changed, seem to affect the internal physiology of the birds!

Herewith an excerpt:

Feather Colors Affect Bird Physiology, Barn Swallows Show

ScienceDaily (Jun. 3, 2008) — In the world of birds, where fancy can be as fleeting as flight, the color of the bird apparently has a profound effect on more than just its image. A new study of barn swallows reveals it also affects the bird's physiology.

A team of researchers, including one from Arizona State University, found in an experiment that involved artificially coloring the breast feathers of male barn swallows the testosterone levels of the manipulated birds soared in a short period of time. The jump in testosterone, recorded after one week, was unexpected because it was observed at the time in the breeding cycle when levels of sex steroids like testosterone are typically declining.

"The traditional view is that internal processes of birds determine their external features -- in other words, physiology forms the feathers," said Kevin McGraw, an assistant professor at ASU's School of Life Sciences. "But our results indicate that a perceived change in the color of an animal can directly affect its internal physiological state. A barn swallow's hormonal profile is influenced by its outward appearance."

"The experimental manipulation didn't just improve the males' looks in the eyes of the females, it actually changed their body chemistry," said lead author Safran.

"The speed with which the internal qualities of the bird were affected by the plumage color manipulation was surprising to me," added McGraw. This suggests a dynamic system, he added, one that "speaks to the complexity of sexual signaling systems and the way people should think about how phenotype interacts with physiology."

The new study is the first to show significant feedback between physical appearance and physiology in birds, and has implications for better understanding the ecology and evolution of physical signals such as feather color, the researchers said.

I am reminded of the Sefer haChinuch’s mantra, אחרי הפעולות נמשכים הלבבות, that our hearts are drawn after our deeds. Apparently, they are drawn after our clothing, too.