Young anorexic women eat almost nothing, are hyperactive and very resistant to fatigue and to infection (at least at first), hide food, worry about others' eating habits, take care of children and often dream of becoming teachers, day care workers, mid-wives, nurses, etc. Very similar behaviours have been observed among female primates when they become interested in their mother or sister's newborn. They eat very little, search for food (a task normally reserved for males), don't have any progeny themselves (anorexics are generally incapable of procreating due to amenorrhoea), are hyperactive, and take care of their mother or sister's young. In primate society, such behaviour is perfectly adapted to the group’s scale because of the risk of famine.

"The analogy between the behaviour of certain female primates and young anorexic women led Albert Demaret to consider that the most important aspect of anorexia was not the refusal to eat, but was rather a form of altruism," explains Jérôme Englebert. He further developed this idea in a 2011 article written with Doctor Jean-Marie Gauthier (ULg) in Acta Psychiatrica Belgica: "These ideas are revolutionary in terms of therapeutic treatment both for the anorexic patient and their family (...) and offer an innovative way of focusing less on the refusal to eat (without denying it) and the loss of weight, and focus instead on other typical signs of anorexia that are too often regarded as secondary."

The territorial advantage

In his other emblematic model, Albert Demaret made an analogy between manic-depressive patients and territorial animals. When animals are in their territory, they display seductive behaviours towards females, are aggressive, successfully challenge peers that are sometimes much larger, and may even decorate certain parts of their bodies in bright colours. But when they cross the Rubicon, they lie low and submit to whatever happens. For Albert Demaret, a manic-depressive patient in the manic phase behaves as if he were in possession of an imaginary territory, as if he were at home everywhere - he is hyperactive, excited, seduces women, and is quick to start a fight... However, when he sinks into a deep depression, he becomes passive, feels that he is uninteresting and without value, and hangs his head as if he were a territorial animal outside of his territory.

"Albert Demaret's analogy may allow us to offer an anthropological critique of modern society," says Jérôme Englebert. “For if we think about it, doesn't the patient in a manic phase correspond perfectly to today's model employee, the one who works 12 hours a day, with enough energy left over to see his friends, go out at night, and then be at work the next day at 7 a.m., perhaps as a trader handling millions of Euros?”

In the article he co-wrote with Jean-Marie Gauthier, Jérôme Englebert emphasised the extent to which the characteristics of a manic person - sure of himself, aggressive, hyperactive, needing very little sleep - can actually serve an adaptive function in extreme situations. The two authors write that "during times of war, such manic performances could continue for a long time (without treatment, manic episodes can last several months), and this kind of hyperactivity, which requires little to no sleep, could offer a protective function for a group that could rest and rely upon these ‘supermen'."