In his recent piece for the New York Times Magazine, Jonah Lehrer describes Charles Darwin's debilitating depression, which involved "hysterical crying" and "bitter mortification," and rendered him "not able to do anything one day out of three." Amazingly, Lehrer goes on to argue that the pain evoked by the depression clarified Darwin's thinking, allowed him to concentrate more fully on his work, and accelerated - rather than slowed - his research.
I highly respect Lehrer's lucid writing and obvious intelligence, but this speculation is astounding in its wrongheadedness.
Far more logical - and consistent with the extant evidence - is the conclusion that Darwin would have been nearly three times more productive had his so-called "fits" not prevented him from working those other two days out of three.
Lehrer's article is about the potential "benefits" of depression and rumination. Much of the theory and empirical research he cites is provocative and accurate. Both emotion researchers and evolutionary psychologists have been arguing for a long time that negative emotions - like sadness, anger, and anxiety - serve important functions. Sadness is a signal that a problem exists to which we need to attend and respond. Research also shows, as Lehrer well describes, that people in a sad mood tend to engage in a relatively slower, more analytical processing style, which, at least under some conditions, leads them to make superior judgments and decisions (such as making fewer stereotypes) than people in a happy mood.
Furthermore, it is undoubtedly adaptive to feel anger when one witnesses injustice (and is thus galvanized to do something about it), and it is adaptive to feel fear in the face of threat or danger (thus prompting action to protect, defend, or run away).
A revealing fact missing from the article is that evidence supporting the functional value of negative emotions mostly comes from studies that induce unpleasant moods in the laboratory - for example, by asking participants to listen to sad music (like Prokofiev's soulful "Russia under Mongolian Yoke," played at half-speed no less) or to recall a situation that made them furious. It goes without saying that clinical depression of the sort experienced by Darwin is not equivalent to the experience of mild transient sad mood.
Lehrer devotes much of his piece to describing a theory of rumination (or overthinking) recently put forward by Paul Andrews and Andy Thomson in the prestigious journal Psychological Review. Rumination triggered by a depressive episode, they argue, actually evolved with a specific purpose - namely, to aid the depressed individual in analyzing her situation, such that she is able to understand it and ultimately fix it. I know something about rumination from having published in the area early in my career, along with my former mentor, Susan Nolen-Hoeksema. What Andrews and Thomson label as rumination is really step-by-step, systematic analysis - also commonly called intellectual self-reflection or simply "problem solving." A growing number of studies have shown that this kind of analytical, reflective thinking has numerous upsides. This is not surprising. By contrast, real rumination - the kind that characterizes many depressed people (and especially depressed women) - leads to nothing positive. Nolen-Hoeksema and I have found, for example, that rumination - defined as passive, perseverative, and intrusive dwelling on oneself, one's feelings, and one's problems (i.e., repetitively going in circles without any insight or resolution) - leads people to become even more depressed, to feel more pessimistic and out of control, and to fare worse, rather than better, at solving the legitimate problems in their lives.
I am in the midst of writing a new book (tentatively titled The Prepared Mind) and coincidentally I happen to be working right now on a short section called "Is There an Upside to Suffering?" My answer to this question, in a word, is "no." There is value to sadness. There is value to recognizing one's own (and the world's) problems and ills. There is value to learning the lesson that life is not always good or fair. But most depression and suffering are agonizing, undeserved, and lead to nothing good.