Recent debate about the new definitions of psychiatric conditions raises some interesting questions about the difference between normal in a natural sense and normal in a statistical sense. As I read through the DSM-5, it seems to me that it reflects the regrettable and increasingly destructive tendency to demonize eccentricity and mislabeloutliers as pathologic.
Nature takes the long view. People (and our human institutions) focus on the near term and dismiss the long term as fantasy or out of reach. Nature thrives on diversity. Natural systems are designed to create variation. People (and our human institutions) prefer predictability and consistency. Where nature depends on mutative change and adaptation based on weeding, people insist on homogenization and adherence to pre-defined standards, and our institutions try to limit changes to those guaranteed to succeed. (This is particularly ironic since we stoutly deny the ability to plan for the long term.)
The human trait of creating order in the midst of chaos by ignoring individual variability or dismissing differences makes sense. It is important to be able to lump ‘plants’ and ‘animals’ and ‘rocks’ and ‘people’ into categories with unifying characteristics. That is how we simplify the world and make it easier to avoid eating rocks or building houses out of people. But we also need to know and respond to the differences within categories, lest we pick poison ivy for our table setting or confuse a porcupine with our pet cat.
While we need to be able to think and work using categories based on commonalities, we must never forget that these categories are artificial. They are designed to obscure the infinite variety within each category and therefore misleading and potentially dangerous. We must avoid the temptation to forget that the benefits of using categories reflects our limited abilities and not the universe in which we live. When we ignore or attempt to constrain the richness within each category and subcategory (fractal variability) we put ourselves at great risk.
The healthiest and happiest individuals are rarely the outliers. (Think of Hamlet, Columbus or Galileo.) Extremes of diversity may not serve the individual well, but for the group (whether an organization or society as a whole) diversity is essential. We need a constant supply of widely divergent options. We need the outliers to discover new paths when the old ones cease to work. Because cease to work they inevitably do.