Loneliness is commonly regarded as a social phenomenon in which individual personality differences contribute to its severity. Some people enjoy solitude, for example, because they never feel lonely, while people with high degrees of loneliness have shorter life expectancies than people who never feel lonely.

There may be more to it than that. Recent research shows that the gene expression in the immune cells of people with chronically high levels of loneliness is different than people who do not feel lonely. Even more telling, some genes were underexpressed in the same subjects, including those in antibody production.

When people in a University of North Carolina at Chapel Hill study were told that anorexia nervosa had a biological or genetics-based cause they were less likely to put any personal accountability on anorexics than when they were told it was personal or cultural.

That makes sense. A disease that is egalitarian and exculpatory like a genetics or biological mutation is different than a syndrome. We can't blame kids with Autism for having Autism, though we do teach them to moderate their behavior - and that's a key point.

Anorexia nervosa is characterized by an obsessive desire to be thin and results in self-starvation and related medical complications.