Molecular (moment‐to‐moment) and molar (aggregate) analyses of behavior
Zoom in to 10 seconds and zoom out to the whole session—then pick the scale that actually drives your treatment.
01Research in Context
What this study did
Shimp (2020) built a computer model that treats moment-to-moment responses and whole-session totals as two views of the same data. The model shows how 10-second event counts and end-of-session sums can live on the same graph.
The paper is conceptual. No kids, no rats, just code. It asks: what if we stop fighting about 'molecular versus molar' and simply toggle the zoom lens?
What they found
The simulation proved that both grains tell the truth. A scallop seen in averaged data also leaves footprints in 10-second bins. You just have to look at both scales before you pick your intervention target.
No numbers are reported; the finding is the method itself. Plot the two views side-by-side and let the data speak.
How this fits with other research
Baum (2002) and Marr (2001) argued that molar data give a cleaner story. Shimp agrees they are useful, but adds the molecular view back in, so the papers do not clash—he simply widens the lens.
Hineline (2001) already said 'use both scales.' Shimp turns that call into a concrete recipe: graph 10-second counts next to session totals.
Critchfield et al. (1999) showed, with one child, that time-allocation patterns match reinforcement ratios at both grains. Shimp's model generalizes that single case to any behavior stream.
Why it matters
Next time you run a functional analysis, plot two lines: one counts every 10 seconds, the other shows the whole session sum. If the microscopic line is flat but the macroscopic line trends up, you know rate is increasing because bouts get longer, not faster. That tells you to target bout length, not inter-response time. You get the insight in under five minutes, before you write the treatment plan.
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02At a glance
03Original abstract
Ten meanings or usages of the terms molecular and molar analyses are based on (1) numbers of responses, (2) durations of activities, (3) levels, (4) scales, (5) contiguity versus correlation, (6) behavioral standards, (7) function with or without structure, (8) local versus global phenomena, and (9) control by shaping of sequential moment-to-moment behavior. These usages reveal divisive viewpoints along with ambiguities in the Law of Effect, the definition of an operant, response strength, response probability, random behavior, time allocation, shaping, controlled versus uncontrolled operants, and roles for ordinary language. Usage 10 is less divisive and combines, and in that sense unifies, molecular behavior, defined as shaped moment-to-moment sequential behaving, and molar, defined as averages of aggregates of those shaped responses. It combines shaping, that establishes and changes operant behaviors, and strengthening that changes the amounts of those shaped behaviors. I conclude that general behavioral theory will combine strengthening with such methods as parametric, hybrid, or nonparametric shaping, and will use computational methods to simulate moment-to-moment behavior streams from which any aggregates of theoretical interest may be computed. Such a synthesis may not require different levels, scales, or new scientific paradigms.
Journal of the Experimental Analysis of Behavior, 2020 · doi:10.1002/jeab.626