To declare your genius...

... just slip on a white lab coat. More than a shield against spills, it signifies membership of an isolated and elite world, argues Maura C. Flannery.

The lab coat is a very persistent symbol of science, even though many scientists never wear one and its popularity is declining among those who traditionally do.

In medicine, where some doctors in the United States import Parisian white coats that have more style than their American counterparts, the white coat is suffering from an interesting schizophrenia. Many doctors and other medical personnel have given up wearing it because of things such as white-coat hypertension and white-coat hyperglycaemia: a worsening of patients' symptoms in the presence of white-cladded figures. It has come to be seen as a symbol of separation and alienation. But, at the same time, a number of medical schools have introduced a ceremony in which first-year students are presented with white coats. So while the reality has changed, the symbolism lives on.

The coat's power is indicated by so-called laboratory chic, which invaded the 1998 autumn fashion season and was characterised by starkly simple white clothes reminiscent of those worn in a Silicon Valley clean room or a germ-warfare laboratory. For the fashion conscious, lab apparel connotes not only cleanliness, but security and peace, as the laboratories and scientists are seen as divorced from normal life. The lab coat that helped to create this image is now being used to symbolise it.

Valerie Steele, of New York's Fashion Institute of Technology, has a darker interpretation. She argues that the lab coat provides "a combination of the minimal and the medical, with a sort of creepy sadomasochistic edge to it, and it plays into our fears about technology and biotechnology. You are choosing to look as though you are the one who has the power over life and death".

She also sees the coat as symbolising control. She is right. Putting on a lab coat is more than just a way to protect against spills. It represents a different way of behaving, a different relationship with other people and with the objects of research. At university, scientists are the only ones who change their dress to do their research. The implication is: "We are not ordinary citizens with emotional problems and worries like everyone else; we are objective and rational scientists who look at the world differently and much more deeply. And this 'better' way of thinking gives us power."

There are some science professors who wear their coats to classes, to meetings and to the cafeteria so that students, colleagues, and even the person who makes sandwiches will be reminded of their status. If asked about this, they will probably reply that it keeps their clothes clean, that it is too much trouble to change or that the pockets are handy for carrying pens. But the fact that those in other disciplines seem to manage without resorting to an extra piece of clothing hints that there may be other reasons for the lab coat's popularity.

It is interesting that it has become such a potent symbol of science considering that it is a rather recent invention. Galileo, Newton and even Louis Pasteur would not have been caught dead in a lab coat. The alchemists wore long, drab robes tied with a cord, like bathrobes. Even in the 18th century, some scientists are still depicted in robes or in the dress of the elite: powdered wig, cutaway jacket, black silk stockings. Portraits of 19th-century scientists tend to show them in standard dress, possibly with an apron on top. Their assistants are more likely to wear grey shop coats under their aprons, indicating the class divide between doers and thinkers.

Shop coats were the precursors of the lab coat, and even early in the 20th century, lab coats were a serviceable brown, blue or grey rather than white. So why did drab but practical colours give way to white laboratory fashion? The proselytising of Sir Joseph Lister, Pasteur and others brought sterile procedure to operating rooms and changed ideas of sanitation in all areas of medicine. White became the symbol of cleanliness in surgical procedure, and the relationship between white and sanitary conditions soon spread to nurses' uniforms and to doctors visiting patients rather than just operating on them.

This trend coincided with the introduction of more laboratories in hospitals for microbiological and pathological testing and for research. As medicine became more scientific and scientists moved into hospitals, scientists took to wearing the same white coats as doctors, partly for efficiency and partly to give themselves added status in the medical community, where they were seen as second class. The lab coat as a status symbol then moved into other areas of science.

There is also a strong psychological attraction to the white coat - it helps people to stand out, and white symbolises goodness, purity and cleanliness. The rise of large, commercial laundries that could keep the coats sparkling was probably also a factor. The popularity of photography helped solidify the lab coat as a symbol in the public's mind - scientists in the news were routinely depicted in white coats, a practice that continues today. It has been argued that the public's understanding of science is so shallow that they know science only in terms of symbols such as the lab coat. For this reason, people have used the coat to add a veneer of scientific gravitas to unscientific endeavours, a practice embraced by the advertising industry.

So the clothes maketh the man. Literally. For a long time, it was only men who wore lab coats because only men became scientists. When I bought a lab coat in college, all the buttons were on the right like a man's shirt, and the coat was cut straight up and down, making no allowance for women's hips. Although lab coats are no longer unisex, they still have a masculine look. As with much else in science, women have had to move toward the male approach to enter the scientific community. Dress was a significant factor in limiting women's participation well into the 20th century. In the 19th century, the long, wide petticoats and skirts worn by middle and upper-class women - the women who would have had the time and means to do science - made doing any kind of work difficult. In the first half of the 20th century, dress was a problem for field biologists.

Feminist critics of science have not been blind to the association of the lab coat with the masculine domination of science. In a 1988 article in Feminist Studies , Ruth Bleier noted that the lab coat "literally and symbolically" wraps the scientist in a robe of "pristine and aseptic neutrality" and gives him "a faceless authority that his audience can't challenge. From that sheeted figure comes a powerful, mysterious, impenetrable, coercive, anonymous male voice."

Other ethnic and racial minority groups have also been under-represented in science. It seems that to gain legitimacy, people must gain acceptance to the elite by taking on the mantle of the lab coat, literally and figuratively. Donning a lab coat suggests that you are entering a different, more serious, more isolated world. It is a physical shield that guards against spills and a figurative one that separates you from the everyday world.

There may also be a romantic aspect to it. Romanticism very much valued the idea of genius, and the public seems to accept that it takes genius to be a scientist. Some may be loath to disabuse people of this assumption, and I think it is they who like to walk around in lab coats - it is their version of the knight's coat of mail, a symbol of the elite of our society, those who protect us, not from other knights but from the dangers of disease and ignorance.

It might be nice to see scientists in this way, but there is a price to pay in terms of alienating scientists from society and fostering the attitude that science is not only difficult to do, but perhaps somehow suspect as well. Scientists are seen as logical and intelligent, but also as lacking in many of the things that make people attractive to each other. It is as if putting on a lab coat causes a personality change, but that is not the case. Rather, those with certain personality traits seem attracted to science. Perhaps the lab coat offers them a degree of protection from the outside world, acting as a shield that proclaims: "Nerd. Do not bother."

Scientists need to see the lab coat not only as a symbol of science, but a symbol of the scientist's relationship with non-scientists. It is a constant reminder that scientists are now somehow different, and it is this sense of difference that makes the public uneasy about them and their work. While scientists are more aware of the problems of communicating their findings to non-scientists, there is still a vast gap between how they perceive themselves and how they are perceived. It is often difficult for scientists to accept that the public's view of science is formed as much by television and movie portrayals of scientists as by textbooks and news stories. The symbolisation of the lab coat indicates just how much they have to do to change their image in the public's mind.

Maura C. Flannery is professor of biology at St John's University, Jamaica, New York.