We animals spend a lot of time grooming, lol. For humans, grooming generally means washing of skin and of clothes. My encyclopedia tells me that bathing, “serving both for cleanliness and for pleasure, has been almost instinctively practised by nearly every people.”
Ancient Egyptians, Greeks, Persians, Jews, Turks, Orientals, and American Indians bathed. The Romans, especially, built elaborate and ingenious baths in which they steamed themselves, scraped their skin with curved scrapers known as strigils, and anointed themselves with fragrant oils.
If chemical communication is so basic, why do humans persist in washing, scrubbing, and deodorizing their bodies? The answer seems to be the same as the answer for grooming behavior in cats and birds: to get rid of ectoparasites and the secretions and shed cells that provide potential substrates for parasites or bacteria.
For humans, washing or airing clothes subjecting them to the deodorant action of ultraviolet light is an important adjunct to bathing to break down or get rid of built-up organic molecules and to avoid reintroduction of parasites.
Although bathing has sometimes been given up (under the guise of saintly behavior in the Middle Ages) or has been discouraged as debilitating (my grandmother felt that frequent bathing had a “weakening” effect), it is a ubiquitous part of the human behavioral repertoire.
Bathing has varied over the centuries with cultural practices, religious belief, location of hot springs, technology for transporting and heating water, climate, and central heating. In cold climates or cold winters when hot water was not just a turn of a tap away, human bathing was more difficult.
My parents talk of the trouble involved in heating water for bathing, especially on wood burning stoves during cold winters. When people possessed fewer changes of clothes, and washing clothes was more difficult and less frequent, we can assume that human odors were much more apparent.
But these were not just pure chemical communication odors; they must have included unpleasant odors associated with the growth of certain bacteria and parasites and with rashes or sores, signals of unhealthiness.
Bathing, along with the sanitary disposal of human feces, has unquestionably contributed to better human health and less itching and scratching. Parasites quickly gain when bathing and clothes washing are suspended, especially when people are crowded together.
Without bathing (and even sometimes with bathing, as elementary teachers who have dealt with classroom lice epidemics will attest), head and body lice, those little medieval “pearls of poverty,” have a heyday.
History, art, and literature abound with examples of human life with ectoparasites and attempts to foil them. Egyptian priests and others have shaved their heads and bodies to keep the lice under control. In the twelfth century, Thomas Becket’s body was observed to “boil over” with lice as it was being prepared for burial, the lice bailing out as his body cooled.