In this episode I unpack one of the foundational articles on precursor assessment in our field:

• Jacoby, P., & Smith, R. G. (2012). Progressing from identification and functional analysis of precursor behaviors to treatment of self-injurious behavior. Journal of Applied Behavior Analysis, 45(4), 767–783.

I frame the article alongside:

• Hanley, G. P., Jin, C. S., Vanselow, N. R., & Hanratty, L. A. (2014). Interview-informed synthesized contingency analysis. JABA, 47(4), 756–775.
• Warner, R. M., Hanley, G. P., & Jarosz, T. (2020). Functional behavior assessment by caregiver interview: Identifying antecedents and precursors. Behavior Analysis in Practice, 13(2), 220–228.

Although many analysts believe an ISCA or open-ended interview is required to examine precursors, I demonstrate that a traditional FA, preceded by careful descriptive observation, is often sufficient—and safer—when the topography is too risky to evoke directly.

2. Why Precursor Assessments Matter

2.1 The Challenge of Severe SIB

When SIB causes tissue damage—eye-poking, head-banging—it can be unethical or unsafe to probe directly in a traditional FA (Iwata et al., 1982/1994). Risk of injury, restraints, or staff reactions can cloud the analysis.

2.2 Functional Response Class Hierarchies

Ordered behaviors sharing a common function vary in intensity (Lerman & Vorndran, 2002). By reinforcing a milder precursor (e.g., knocking) you can prevent escalation to dangerous behavior (e.g., breaking a window).

2.3 Advantages of Precursor-Based FA

• Avoids evoking dangerous topographies
• Reduces need for blocking or restraints
• Builds positive history of safer alternatives
• Maintains experimental control to identify function

3. Article Summary: Jacoby & Smith (2012)

3.1 Purpose & Aims

1. Identify a reliable precursor via descriptive observation
2. Conduct FA on that precursor
3. Develop a function-based treatment targeting the precursor
4. Evaluate whether reducing the precursor reduces SIB

3.2 Participant & Setting

“Peter,” a 29-year-old man with profound intellectual disabilities; SIB ~2×/day in his residential behavior-therapy room.

3.3 Descriptive Assessment

They identified a “head-up” movement that reliably preceded each SIB episode, meeting criteria for a valid precursor.

3.4 Functional Analysis of the Precursor

FA conditions (attention, escape, tangible, alone) were structured around the head-jerk; data showed it was escape-maintained.

3.5 Treatment Development: Precursor FCT

Designed an FCR for escape, extinguished the head-jerk, reinforced the FCR, and implemented graduated demands.

3.6 Generalization & Maintenance

Precursor rates dropped 80%; severe SIB fell to near zero across settings and staff.

4. Context Within ABA Literature

• Traditional FA (Iwata et al., 1982/1994)
• Interview-Informed Synthesized Contingency Analysis (Hanley et al., 2014)
• Caregiver Interview for Precursors (Warner et al., 2020)
• Other methods: CSIA, momentary sampling, video lag-sequential analysis

5. Practical Considerations for Clinicians

5.1 When to Look for Precursors

Any behavior too risky or painful to evoke directly (elopement, property destruction, SIB).

5.2 Identifying Precursors

• Descriptive observation (5×30-min sessions)
• Validate by Pr(SIB | precursor) ≥ .80

5.3 Conducting a Precursor FA

Define strict operational criteria; evoke the precursor safely; collect rate data across conditions.

5.4 Designing the Treatment

• FCT for break requests if escape-maintained
• Attention card or microswitch if attention-maintained
• Communicative gesture for tangibles if tangible-maintained

5.5 Monitoring Generalization & Maintenance

• Train all staff on detection and prompting
• Fade prompts, increase independence
• Collect natural-setting SIB data

6. Key Takeaways

• Focus on precursors, not dangerous topographies, to analyze function.
• Use functional response class hierarchies to identify safer alternatives.
• Reducing precursors prevents escalation to high-risk behaviors.
• Precursor assessments enhance safety and feasibility of FAs.
• Jacoby & Smith (2012) remains the exemplar approach.

7. References Mentioned

• Carr, E. G. et al. (1998). Relationship of precursor behaviors and self-injury. JABA, 31(3), 375–378.
• Hanley, G. P. et al. (2001). Toward a FA of self-injury. JABA, 34(1), 31–58.
• Hanley, G. P. et al. (2014). ISCA. JABA, 47(4), 756–775.
• Iwata, B. A. et al. (1982/1994). Toward a FA of SIB. JABA, 27(2), 197–209.
• Jacoby, P., & Smith, R. G. (2012). FA of precursor behaviors to treatment of SIB. JABA, 45(4), 767–783.
• Lerman, D. C., & Vorndran, C. M. (2002). Functional response classes. JABA, 35(4), 397–404.
• Warner, R. M. et al. (2020). Caregiver interview for precursors. Behavior Analysis in Practice, 13(2), 220–228.