Poisoned Cues in Animal Training: What They Are and Why They Matter
By Abigail Greenwalt, R+ Trainer & Animal Science Educator
π What Is a Poisoned Cue?
A poisoned cue is a signal that has been associated with both reinforcement and aversive consequences. While a cue should signify a chance to earn reinforcement, a poisoned cue leaves the learner unsureβ"Is this going to be good, or bad?"
Coined by Karen Pryor, a poisoned cue is a discriminative stimulus (SD) that predicts mixed outcomes. The result? Stress, hesitation, and degraded performance.
βA poisoned cue is one that has been used with both reinforcement and punishment, making the animal unsure of whatβs coming next.β β Karen Pryor, 2002
π§ The Research Behind Poisoned Cues
1. Murrey (2007) Thesis
A poodle trained with both R+ and leash corrections became avoidant. The cue, associated with punishment, failed to function as a reinforcer.
π Read the thesis
2. Ven vs. Punir Study (Rosales-Ruiz)
"Ven" (R+ only) led to fluent chains. "Punir" (with punishment) caused freezing.
π₯ Watch the webinar
3. Hearst & Sidman (1961)
In rats, a cue predicting both reward and shock became aversive.
π Read abstract
4. Wassum et al. (2019)
Humans and animals respond emotionally to cues with uncertain outcomes.
π PubMed article
𦀠Real-Life Horse Examples
Poisoned cues are common in crossover horses. Here are a few:
βCluckβ or βKissβ β Previously sometimes paired with whips or spurs.
Lead Rope Pressure β Taught through Rβ, now met with bracing.
Backing Up β Previously involved correction; now causes anxiety.
Grooming/Touch β History of forced desensitization.
Mounting Block β Horse associates mounting with tension.
Voice Cues β Linked with shouting or punishment.
Even environments can become poisoned: arenas, saddles, halters.
π What Are the Effects?
Signs of poisoned cues:
Inconsistent performance
Freezing before/after the cue
Avoidance or distractibility
Emotional shutdown or hyperactivity
βοΈ How to Fix a Poisoned Cue
β Best Fix:
Replace the cue completely
Use only R+ to teach new behaviors
π§ Repairing a Cue:
Isolate the cue
Remove aversive associations
Rebuild with R+ only
Focus on emotional safety
Resources:
π Learn More in the Greenwalt Equine Membership
Iβm building a full Poisoned Cues course inside my membership. It includes:
Understanding poisoned cues
Identifying poisoned cues
Preventing poisoned cues
Cue repair strategies
π Click here to join the waitlist and get notified when itβs live!
Poisoned cue repair:
https://tagteachblog.com/the-poisoned-cue-and-you/
https://clickertraining.com/poisoned-cues-the-case-of-the-stubborn-dog/
https://eileenanddogs.com/blog/2019/10/28/replace-retrain-poisoned-cue/
https://stalecheerios.com/training-concepts/thoughts-poisoned-cues/
https://behaviorexplorer.com/summer25/