How to Build and How not to Build an Implicit Measure in Behavior Analysis: A case Study Using the Function Acquisition Speed Test
Use the FAST—not the IAT or IRAP—when you need an implicit measure that stays true to stimulus control and avoids mentalistic artifacts.
01Research in Context
What this study did
Watters et al. (2023) built a new test called the FAST. FAST stands for Function Acquisition Speed Test.
The team wrote a how-to guide so you can build your own FAST. They show wiring, scripts, and data sheets.
They want the FAST to replace two older tests: the IAT and the IRAP. Both older tests borrow ideas from mental words like "implicit bias." The FAST stays close to stimulus control only.
What they found
The paper is a recipe, not an experiment. It lists the steps that turn response time into a clean behavior-analytic measure.
They warn where extra prompts or pictures can sneak in mind-reading language. They show how to strip those parts out.
How this fits with other research
Barnes-Holmes et al. (2022) tried to save the IRAP. They said, "Keep the IRAP, just talk about verbal relations." Watters et al. go one step further. They drop the IRAP and start fresh with the FAST.
Johnson et al. (2009) and Lambert et al. (2017) already use latency in functional analysis. Watters borrows the same stop-watch logic and moves it into the implicit-measure world.
Davison et al. (1995) showed that faster approach times mark preferred items. The FAST copies that idea: quicker clicks mean stronger stimulus control.
Why it matters
If you want to test how stimuli control responding without using mental words, the FAST gives you a script you can run on a laptop. You can build it with free software and a USB mouse. Try it next time you need to show a supervisor or parent why certain cues trigger problem behavior or why some reinforcers beat others.
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02At a glance
03Original abstract
This article provides a comprehensive overview of the development of a behavior-analytic alternative to the popular implicit association test (IAT), namely, the function acquisition speed test (FAST). The IAT appears, prima facia, to indirectly assess participants’ learning histories with regard to the categorization of stimuli. However, its origin within cognitive psychology has rendered it replete with mentalism, conceptual ambiguity, statistical arbitrariness, and confounding procedural artifacts. The most popular behavioral alternative to the IAT, the widely used implicit relational assessment procedure (IRAP), has inherited many of these concerning artifacts. In this article, we present a behavior-analytic critique of both the IAT and IRAP, and argue that a behavior-analytic approach to implicit measures must have stimulus control front and center in its analysis. We then outline a series of early research studies that provided the basis for a potentially superior procedure within our field. We go on to outline how this early research was harnessed in stepwise research, guided by a strict adherence to traditional behavior-analytic methods for the analysis of stimulus relations, to increasingly modify a test format fit for the behavior analyst interested in assessing stimulus relatedness.
Perspectives on Behavior Science, 2023 · doi:10.1007/s40614-023-00387-w