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Losing Our Minds

October 3, 2014

By Barbara Demeneix, Professor of Comparative Endocrinology and Physiology at CRNS and Muséum National d'Histoire Naturelle de Paris. She is the author of Losing Our Minds: Effects of Chemical Pollution on the Intellectual Capacity and Mental Health of Future Generations, available on Oxford Scholarship Online.

Losing Our Minds

A number of indicators show that not only is neurodevelopmental disease increasing, with different types of behavioral and intellectual disorders affecting up to 1 in 6 children, but that there is also a concomitant decrease in IQ scores in developed countries. Recent studies show that incidence of Autism Spectrum Disorder (ASD) has reached 1 in 42 boys in the US; whilst other research documents decreases in IQ of up to 16 points over the last century. Clearly these trends have multifactorial causes. Currently, most research effort is directed primarily at unraveling genetic causes to understand and explain the increased incidence in neurodevelopmental disorders, including ASD. However, it is evident that the human genome is not evolving at a rate to account for the rise in incidences, even if one takes into account multiple, interacting genetic variations. The principal alternative hypothesis is that environmental causes are implicated.

 In Losing Our Minds I set up and discuss the hypothesis that two major environmental factors are interacting synergistically and adversely affecting early brain development, particularly during intra-uterine growth.  These two factors are chemical pollution affecting thyroid hormone signaling and iodine lack.  This hypothesis is based on the well-established facts that thyroid hormone is essential for brain development and that iodine is needed to make thyroid hormone. In previous centuries, lack of iodine, and therefore lack of thyroid hormone, during development gave rise to a severe disorder: cretinism.  Cretinism is a severe form of intellectual disability coupled with stunted growth. As iodine is a relatively rare element, especially in mountainous inland areas distant from the sea, cretinism was more common in these regions. 

Today, for a number of reasons, mainly neonatal screening for thyroid hormone disorders, cretinism has been eradicated in most developed countries. However, it is increasingly documented that iodine lack in pregnancy can adversely affect children’s development and later IQ, potentially leading to a silent spread of ‘mild, surreptitious cretinism’. 

Besides iodine lack, the other factor contributing to population level decreases in IQ and increased neurodevelopmental disease, is the action of endocrine disrupting chemicals, particularly chemicals that affect thyroid hormone action.  A number of authors have argued that more chemicals present in the environment affect thyroid hormone action than any other endocrine signal (for instance estrogens and androgens). This marked sensitivity of thyroid hormone signaling to chemical pollution is due to the multiple, complex mechanisms implicated in thyroid hormone synthesis, distribution around the body and action in target tissues. A large spectrum of chemical categories can affect thyroid hormone signaling including: flame-retardants (used in upholstery and furniture), surfactants (used in non-stick pans, waterproofing products etc.), pesticides, plasticizers (including phthalates), anti-microbial agents, nitrates (derived from fertilizers) and perchlorate (used as an explosive and in the space industry). Another environmentally-relevant contaminant that can affect thyroid hormone signaling is mercury, produced from coal-fired power stations and other industrial activities.

Many of these chemicals pass the placenta and are found in amniotic fluid. Thus, current generations are exposed to significant amounts of these chemicals from conception onwards. If the mother is also lacking iodine, the assault on thyroid hormone signaling and the baby’s brain is double.

Clearly, there is a need first, to ensure that women contemplating pregnancy have access to nutritional supplements that contain iodine and second, to determine which chemicals are the most dangerous and to legislate for their control. 

One of the easiest and cost effective means ensuring that populations are iodine sufficient is to legislate in favor of the use of iodized salt in households and in the food industry. Many countries, particularly in Europe, no longer have legislation covering mandatory use of iodized salt. For instance, it is increasingly difficult to obtain iodized salt in UK supermarkets. Further, many consumers prefer to buy sea salt, that, contrary to popular belief, does not contain iodine because it is lost during sea salt production.

These factors contribute to the fact that Western populations are increasingly iodine deficient and this is particularly dangerous given that the populations are increasingly exposed to chemical pollution. There is thus an urgency to protect the intellectual potential and mental health of future generations by providing information for consumers and introducing effective legislation at national and international levels. Losing Our Minds concludes with a discussion of how these aims can be achieved.


If objective moral reasoning is possible, how does it get started?  Sidgwick’s answer is, in brief, that it starts with a self-evident intuition. He does not mean by this, however, the intuitions of what he calls “common sense morality.”  To see what he does mean, we must draw a distinction between intuitions that are self-evident truths of reason, and a very different kind of intuition. This distinction will become clearer if we look at an objection to the idea of moral intuition as a source of moral truth.

Sidgwick was a contemporary of Charles Darwin, so it is not surprising that already in his time the objection was raised that an evolutionary view of the origins of our moral judgments would completely discredit them. Sidgwick denied that any theory of the origins of our capacity for making moral judgments could discredit the very idea of morality, because he thought that no matter what the origin of our moral judgments, we will still have to decide what we ought to do, and answering that question is a worthwhile enterprise.

On the other hand, he agreed that some accounts of the origins of particular moral judgments might suggest that they are unlikely to be true, and therefore discredit them. We defend this important insight, and press it further. Many of our common and widely shared moral intuitions are the outcome of evolutionary selection, but the fact that they helped our ancestors to survive and reproduce does not show them to be true.

This might be taken as a ground for skepticism about morality as a whole, but our capacity for reasoning saves morality from this skeptical critique. The ability to reason has, of course, evolved, and clearly confers evolutionary advantages on those who possess it, but it does so by making it possible for us to discover the truth about our world, and this includes the discovery of some non-natural moral truths.

Sidgwick thought that his greatest work was a failure because it concluded by accepting that both egoism and universal benevolence were rational. Yet they pointed to different conclusions about what we ought to do. We argue that the evolutionary critique of some moral intuitions can be applied to egoism, but not to universal benevolence. The principle of universal benevolence can be seen as self-evident, once we understand that our own good is, from “the point of view of the universe” of no more importance than the similar good of anyone else. This is a rational insight, not an evolved moral intuition.

In this way, we resolve the so-called “dualism of practical reason.” This leaves us  with a utilitarian reason for action that can be presented in the form of a utilitarian principle: we ought to maximize the good generally.

What  is this good thing that we should maximize? Is my having a positive attitude towards something enough to make bringing it about good for me? Preference utilitarians have argued that it is, and one of us has, for many years, been well-known as a representative of that view.

Sidgwick, however, rejected such theories, arguing that the good must be, not what I actually desire but what I would desire if I were thinking rationally. He then develops the view that the only things that it is rational to desire for themselves are desirable mental states, or pleasure, and the absence of pain.

For those who hold that practical reasoning must start from desires, it is hard to understand the idea of what it would be rational to desire – or at least, that idea can be understood only in relation to other desires that the agent may have, so as to produce a greater harmony of desire.

This leads to a desire-based theory of the good.

One of us, for many years, became well-known as a defender of one such desire-based theory, namely preference utilitarianism. But if reason can take us to a more universal perspective, then we can understand the claim that it would be rational for us to desire some goods, even if we have no present desire for them. On that basis, it becomes more plausible to argue for the view that the good consists in having certain mental states, rather than in the satisfaction of desires or preferences.

- See more at: http://blog.oup.com/2014/06/the-point-of-view-of-the-universe/#sthash.LhtDta11.dpuf



Discover more: the chapter 'Chemical Pollution and IQ Loss in Children: Learning from the Past' in Losing Our Minds: Effects of Chemical Pollution on the Intellectual Capacity and Mental Health of Future Generations is now free and available to read until the end of October. Get access to the full text of this book, as well as more than 500 other Oxford Psychology titles, by recommending OSO to your librarian today.