We live in an age of pictures rather than words. The result? Assertive women and a return to Goddess worship. Leonard Shlain reports

On a tour of Mediterranean archaeological sites a few years ago, I was drawn into a mystery. At nearly every Greek site we visited, our guide patiently explained that the shrines we stood before had originally been consecrated to a female deity, then later, for unknown reasons, they were reconsecrated to a male deity.

While there is overwhelming archaeological and historical evidence that both men and women once worshipped goddesses in the ancient western world, no one knows why goddesses abruptly disappeared. That question was to hover over the entire trip. What cultural event could have been so immense as to change the sex of God?

According to the most commonly accepted theory, just before recorded history began, invading horsemen from the north imposed their sky gods and virile ethics on the peaceful goddess cultures they vanquished. But this explanation seemed inadequate to explain a widespread phenomenon that took a millennium to unfold. On the trip back to the airport, it struck me that the demise of the Goddess and the advent of misogynist patriarchy occurred around the time people were first learning how to read and write. Perhaps something about the way humans acquired literacy offered a key to the mystery.

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As a vascular surgeon operating on carotid arteries that supply blood to the brain, I have observed the profoundly different functions performed by each of the brain's hemispheres. I also know that in the developing brain of a child, different kinds of learning strengthen some neuronal pathways and weaken others. Extrapolating from the individual to a culture, I arrived at my own hypothesis to explain why goddesses had disappeared, one that takes into account both neuroanatomy and the historical appearance of the alphabet.

My theory is that certain masculine characteristics begin to characterise a society after a critical mass of its people learn to read and write. What triggers this profound shift is literacy's reliance on the analytic thought processes linked to the brain's left hemisphere. Meanwhile, the feminine traits associated with the right hemisphere are systematically devalued. This imbalance reveals itself in many ways, including a cultural decline in goddess worship and the status of women. Another outcome is a new disregard for the visual image, whose appreciation is closely tied to the right hemisphere.

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Any society introduced to the written word experiences explosive changes, and for the most part these changes can be called progress. Indeed, of all the sacred cows in our culture, few have been as revered as literacy in the five millennia since its advent.

Few, however, have paused to consider its costs. Only by understanding the real impact of alphabet literacy can we grasp the unique situation that exists today, as we witness a return of the image via photography, film, television and the computer. The rise of new visual technologies has been accompanied by a resurgence of feminine values, holistic thinking and respect for nature. I would argue that the visual media are largely responsible for this revolution in values, though not simply because of the information they convey. A greater factor may be the way they actually reprogram our brains.

How could a culture's dominant mode of communication, its choice of either pictorial or alphabetic modes, affect the balance of power between the sexes? The key may lie in the human nervous system. The two hemispheres of the human brain, while they appear to be symmetrical, are functionally different. The right hemisphere integrates feelings, recognises images and appreciates music. It enables the mind to grasp the input of our senses all at once. It is also more involved in generating "feeling" states such as love, humour, or aesthetic appreciation, which defy the rules of conventional reasoning.

The left brain's primary functions are opposite and complementary to those of the right. The left brain largely knows the world through its unique form of symbolisation - speech. It uses words to discriminate, analyse and dissect the world into pieces, objects and categories. Analysis - reducing the components of sentences into their separate parts - is essential to understanding speech. This key left brain task depends upon linear progression, in contrast to the holistic thinking of the right brain.

A bridge of neuronal fibres called the corpus callosum connects the two hemispheres, so that each knows what the other is doing. Researchers have discovered that women have between 10 and 33 per cent more neuronal fibres in the forward part of their corpus callosum than men. A greater integration between the hemispheres may contribute to women's better perception of feelings and their enhanced global awareness. A woman's ability to understand the moods of her offspring must have increased their chances of survival. Although the evolving male paid a price for relative isolation from his right-brain emotions, he gained the ability to shut out feelings that might otherwise have distracted him while he was engaged in that most dangerous activity, the hunt.

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We remain strongly influenced by the original neurodesign that bred successful nomadic hunter-gatherers. The feminine outlook is holistic, simultaneous, synthetic and concrete, whereas the masculine view is linear, sequential, reductionist and abstract. Every newborn is endowed with a brain that embodies both modes of thought.

But human brain development is not complete at birth. We enter the world as works in progress, waiting for family and culture to add the finishing touches. A third shaping force, almost as important, is the principal medium through which the child learns to perceive his culture's information. This medium - pictorial or alphabetic - plays a role in determining which neuronal pathways of the child's developing brain will be reinforced: those that process images or those that process words.

The precursors of writing were pictographs, which, like every other visual art form, fall primarily under the right brain's purview. The alphabet, in contrast, is a set of linearly arranged abstract symbols assigned to represent the basic sounds of speech.

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Alphabetic literacy caused a biological effect that led to a fundamental change in the way cultures understood their reality. Some neuropathways in the brain were reinforced while others withered. Goddess worship, feminine values, and women's power depended on the ubiquity of the image. God worship, masculine values and the paradigm of patriarchy rose with the written word. This was, and is, literacy's hidden cost.

The three dominant religions of the West, Judaism, Christianity and Islam are each based on an alphabetic sacred text. Each denies the existence of goddesses, relegates women to subservient roles and denigrates images while extolling the importance of the written word. Whenever literacy rates fell, as they did in the Dark Ages, women's status increased, and it was during this period that Medieval Europe elevated the Virgin Mary to a preeminent position. When Gutenberg invented his printing press in the Renaissance, literacy rates soared in Europe and it was then that the witchhunts began in earnest. They were most virulent in Germany, Switzerland and France, countries that experienced the steepest rise in literacy rates. Russia remained essentially illiterate during this same period and did not experience a witchcraze.

We are living in an age dominated by images brought to us by visual technologies such as photography, film, television and the computer. This is also the time that women are reclaiming rights they held long ago. Men are embracing feminine values such as honouring the earth instead of trying to subdue it. I propose that it is the often-overlooked feature of our technology, the shift from page to screen, that is realigning culture by balancing our cerebral hemispheres.

Leonard Shlain is chief of laparoscopic surgery at the California-Pacific Medical Center, San Francisco. His book, The Alphabet Versus the Goddess: Male Words and Female Images, is published by Penguin Press.

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