Ontogeny, mechanism, phylogeny, and function

From The Why is Not the Same as the How: Levels of Analysis and Scientific Progress in Psychology by Laith Al-Shawaf.  The author is arguing that a conceptual model originating in the field of biology would also bring value to the muddied and inchoate field of psychology.  

She has a horrifyingly good opening example and then a clear explanation of the model she is advocating.

The emerald-colored jewel wasp (Ampulex compressa) parasitizes the common cockroach with a sophistication that beggars the imagination. Here’s how the morbid scene unfolds. The wasp begins by injecting a venomous compound into the roach’s body, temporarily paralyzing its victim. Next, it seeks out two specific areas of the roach’s brain, injecting them with a custom-made neurochemical cocktail. This injection has a surgically precise effect: it leaves the roach’s motor abilities intact, but robs it of its will to escape—an astonishing combination that will become important later. Finally, the wasp delivers its coup de grâce: it drags the zombified roach to its grave, deposits an egg on it and buries it alive. Why does the wasp bother to do these specific things in this exact sequence?

Sixty years ago, the great ethologist Niko Tinbergen argued that in order to achieve a complete understanding of any biological trait or system, we have to answer four separate questions: (1) how the system develops during an organism’s lifespan (known as ontogeny or development); (2) how the system works in the immediate present (mechanism or immediate causation); (3) how the trait evolved over time (phylogeny); and (4) why the trait evolved (its function or adaptive value). These four questions—ontogeny, mechanism, phylogeny, and function —represent different “levels of analysis.” Tinbergen’s key insight was that if you want to understand something about an organism, you need all four levels of analysis.

These four levels can be collapsed into two broader categories known as the proximate and ultimate levels of analysis (see also Mayr 1961). The proximate level consists of ontogeny and mechanism, which deal with how the trait developed during an organism’s life and how it works in the immediate present. The ultimate level consists of phylogeny and function, which are about how and why the trait evolved. Proximate explanations explain how something works—for example, how the liver works, or what causes the sucking reflex in infants. Ultimate explanations explain why the system works that way, or why it exists in the first place—for example, why we have a liver (to filter blood, detoxify poisons and facilitate digestion) or why the sucking reflex evolved (to facilitate breastfeeding). The proximate and ultimate levels of analysis answer different questions about the same phenomenon, and both are crucial to a complete understanding of the phenomenon.

I don't disagree with the argument and the field of psychology could do with a lot more rigor of conceptual thinking.

My only discomfort arises from experience with problem solving in enterprises where there tend to be multi-levels of root cause and the deeper in you get to a root the more often you transition from tactical to strategic.  

Hypothetical:  Your production line used to have a 1% failure rate and it has risen to 10%.  10% of final product has to be either tossed or manually fixed or repaired.  That it an unacceptable cost burden.  One technique for determining where the failure rate occurs is the seven whys of problem solving.  For each answer, drive backwards six levels by asking why to get to root causes (ultimate causes).  

Q:  Why is there 10% failure rate?

A:  70% of the discards are due to poor epoxy application.

Q:  Why is epoxy application responsible for 70% of the discards?

A:  Because the epoxy spray jets apply an uneven level of epoxy.

Q:  Why do the epoxy jets apply an uneven level of epoxy?

A:  Because we are using a more viscous form of epoxy.

Q:  Why are we using a more viscous form of epoxy?

A:  Because we had to reduce costs. 

Q:  Why did we have to reduce costs?

A:  It was an edict from headquarters.

Q:  Why did headquarters issue that edict? 

A:  We were losing sales.

Q:  Why were we losing sales?

A:  Because our product offered the same functionality as our competitor but at a higher price.

As you can see, it can be a rich discussion.  Each layer of the seven whys can start a whole different train of whys.  In this case, we go from very tactical issues of failure rates and production problems to the strategic issues of product price, quality and brand.  But where is the transition from proximate to ultimate?

It is not a disabling question, just an issue.  I think that Al-Shawaf is correct, the four component model - ontogeny, mechanism, phylogeny, and function - can be productively extended to other fields with an evolutionary dynamic.  How it can be done effectively is a different question.  A proximate question.