Nassim Taleb has the best definition of "nerd" that I've ever come across. Nerds are people who cannot think outside whatever box they've been given. Engineers, physicists, mathematicians, IT professionals and many economists all make fine nerds. They perform expert, high-level operations within the confines of what can be exceptionally narrow disciplines -- and have little ability to think outside that domain.
What nerds do can be impressive, but it's important to understand why. Nerds do impressive feats that require computational brute-force and only apply to very specific activities. They fail, however, when trying to move beyond the confines of their specialties. They lack flexibility and the capacity to break context.
The word "systemizer", so far as I can tell, was coined by psychologist Simon Baron-Cohen (not to be confused with the guy who played Ali G and Borat) in his work with children who have autism spectrum conditions. The term "systemizer" is meant to capture the most striking feature of these children, which can be loosely summarized as a drive to discover regularities, orderly rules, and details.
‘Systemising’ is the drive to analyse the variables in a system, to derive the underlying rules that govern the behaviour of a system. Systemising also refers to the drive to construct systems. Systemising allows you to predict the behaviour of a system, and to control it.
Baron-Cohen's empathizing-systemizing theory is meant to explain these conditions on the autism spectrum as a deficit in empathy, along with intact or even improved systemizing skill. These hyper-systemizers find it difficult to cope with uncertainty and change.
I don't mean to draw a connection between nerd-ish behavior and autism spectrum conditions (although they may represent different degrees of a related mechanism), but rather to illustrate the particular frame of mind: the drive to construct systems, to predict, and to control.
There are domains where this is a valuable skill. Any technical, logical-mathematical, or otherwise systematic discipline will benefit from thinking like a nerd. The problem for the nerd arises in situations typified by wildly variable, uncertain, and unpredictable behavior. The need for order and rules becomes a liability.
Unfortunately, variable, uncertain, and unpredictable are qualities that describe most every type of Interesting Thing in the world. Weather, economics, social systems, mind and consciousness, all of these things share a set of features common to complex adaptive systems. As we're coming to understand, these features apply just as readily to life.
Life is squishy, dynamic, and constantly changing, and yet our best metaphors still rely on the imagery of machines and computers. As a group we are nerds of the worst type, attempting to take this chaos and fit it into our rigid models that describe a non-existent world of regularities. We're trying to take the waft and flux of existence, take it apart, and capture its essence in a set of equations.
Biological systems are physical systems, and they are entirely explainable by the laws of the natural world -- cell biology, chemistry, and if you're willing to go all the way down, physics. That said, I do not believe that living organisms are reducible to chemistry or physics.
Here we have an issue of terminology worth a brief digression. The phrase "explainable by" differs from "reducible to" in a subtle but important way. If I tell you that I can explain a broken window, you probably won't be surprised when I point at a brick lying a few feet away. The brick, and our background knowledge about motion and glass and bricks, makes the connection obvious; in that sense we have "explained" your broken window. In a similar way, our background knowledge about physics and chemistry "explains" biological systems.
Explanation does not imply that living organisms are reducible to physics and chemistry. You don't derive the laws that govern living beings, or predict their behavior, or even describe their features, by looking at their biochemical pathways. Physics and chemistry simply don't -- cannot -- capture the relevant properties. Those properties only emerge at a larger scale, from the behavior of the system-as-a-whole.
In a very real sense, our attempt to measure, to quantify, to objectify the world of complex phenomena backfires, convincing us that we've understood a thing when in reality we've only captured a limited aspect of it.
You might read this as an anti-science argument, and I can see the hackles going up on all the Rational Skeptics and New Atheists, so let me qualify. Biology is an empirical science, and investigating biology on many levels, from the top down, has given us a wealth of knowledge and will continue to do so. I'm arguing that, for science to be useful, this toolkit has to be used with care.
Otherwise you end up with the various internet fantasies pulled out of Pubmed and posing as "scientific facts". This tendency strays dangerously close to an attitude of scientism. That word can mean lots of things, though it is typically used as an attack on the over-reach of scientific methodology and authority into domains where it may not apply. We see this in, for example, attempts to take methods that have proven successful in physics and chemistry and extend them to social sciences.
I'm not quite going that far since I believe that biology is, and should be, an area of scientific investigation. The scientism I'm describing has more to do with the excessive weight placed on scientific (and, crucially, scientific-sounding) claims, and in particular, the tendency to explain biology in reductionist terms.
As far as I'm concerned, this is a viewpoint that has no relevance outside the mind of the systemizing nerd. Nerds want control and predictability, so they cook up models that give them that control. Whether or not they reflect reality is beside the point.
Biology is not physics. Biology is not reducible to physics. To understand the operation of living organisms, we have to study living organisms. In applied biology, as we have in nutrition and exercise science, this is even more true. You will not adequately express the behavior of a living system with neat rows of numbers and lists of molecular signals.
The scope of the systemizing nerd extends beyond reductionism. The unchecked extrapolation from a very incomplete science is a central problem in many areas of exercise and nutrition, as is the unfounded certainty granted to "facts" simply because they appear in published research. In future posts I hope to address the limits of science-as-method as well as issues with empiricism itself.
Without a critique of science, we're left with Pubmed fantasies. These may give you comfort and an illusion of knowledge, but as a reflection of the natural world, they miss the mark in a fundamental way.
Complexity in biology (may require a subscription)
Reductionism in Biology (more technical, for the brave)
(For anyone interested in a more technical discussion of these ideas, search for the terms "supervenience", "top down causation", or "nonreductive physicalism" along with "biology" in Google Scholar or your choice of academic database.)