The following discussion is informed by applied behaviour analysis and learning theory, particularly the work of Friedman (2009, 2010), Skinner (1953), Pavlov (1927), and contemporary interpretations of marker-based training.

When we talk about using a marker (like a clicker), it’s helpful to understand what role it is playing at different stages of learning, because that role changes over time (Skinner, 1953, Pryor, 1999).

1. The Clicker as a Conditioned Stimulus (Respondent Conditioning)

Initially, the marker is part of respondent (classical) conditioning.

• Click → food

At first, the click is a neutral stimulus (NS). Through repeated pairing with food, it becomes a conditioned stimulus (CS), capable of eliciting the physiological response of salivation, in the same way demonstrated in Pavlov’s classical conditioning experiments (Pavlov, 1927).

At this stage, the click predicts food.

2. The Clicker as a Conditioned Reinforcer (Operant Conditioning)

Once conditioned, the click becomes a conditioned reinforcer because it has been paired with positive reinforcement (Skinner, 1953; Pryor, 1999)..

This creates an ABC contingency, Antecedent: Behaviour-Consequence:

• Antecedent No.1: Trainer says sit

• Behaviour No. 1: Dog sits

• Consequence No. 1: Trainer clicks the clicker (conditioned reinforcer)

• Antecedent No. 2: Trainer clicks the clicker

• Behaviour No. 2: Dog looks up at trainer’s face

• Consequence No. 2: Trainer delivers food to the dog (unconditioned reinforcer)

Both the click and the delivery of food function as consequences that increase the likelihood of the sit and look behaviour occurring again, demonstrating operant conditioning in action (Skinner, 1953).

3. There Are Always Smaller ABCs Inside the Big One

As Dr. Susan Friedman explains, behaviour happens in very small units (Friedman, 2009, 2010).

Just as Pavlov’s dogs weren’t standing still salivating (they were orienting, turning heads, shifting posture, tapping feet), our dogs are also performing many micro-behaviours within what looks like a single response (Pavlov, 1927; Friedman, 2010).

Within:

“Trainer says sit → dog sits → click → feed”

There are many more behaviours, for example:

• Movement of the ears

• Eye movement

• Movement of the nostrils

• Movement of the feet and limbs

These are all operant behaviours, learned through consequences.

4. The Clicker Can Become an Antecedent

Although the click starts as a consequence, it can also function as an antecedent for the next behaviour.

Let’s look again at that same example:

• Antecedent No.1: Trainer says sit

• Behaviour No. 1: Dog sits

• Consequence No. 1: Trainer clicks the clicker

• Antecedent No. 2: Trainer clicks the clicker (discriminative stimulus)

• Behaviour No. 2: Dog looks up at trainer’s face

• Consequence No 2: Trainer delivers food to the dog

In gundog work, this is particularly relevant when the dog is working at a distance (e.g., during a water retrieve). A marker or signal with a reinforcement history can act as a discriminative stimulus, prompting the next behaviour in the sequence, such as turning, looking at the handler and returning to the handler (Skinner, 1953; Pryor, 1999).

Over time, the clicker may function sequentially as:

1. A conditioned stimulus

2. A conditioned reinforcer

3. A discriminative stimulus (antecedent)

5. Other Things Can Accidentally Take the Clicker’s Place

If the clicker is removed intermittently or omitted, other stimuli may begin to occupy the same functional role in the learning sequence.

Example:

• Antecedent No 1: Trainer says sit

• Behaviour No. 1: Dog sits slowly

• Consequence No. 1: Trainer reaches for their treat pouch with their hand

• Antecedent No. 2: Trainer reaches for their treat pouch with their hand (discriminative stimulus)

• Behaviour No. 2: Dog looks toward the hand moving to the pouch

• Consequence No. 3: Trainer delivers food to dog

With repetition, the dog may learn:

“Dog sits slowly → hand moves to treat pouch → food”

In this case, the hand movement becomes a discriminative stimulus. While this is not inherently problematic, it becomes significant depending on which behaviour it is cueing and under what conditions (Friedman, 2010).

6. Overshadowing and Why It Matters

Hand movement can overshadow the clicker because it is:

• More visually salient

• Temporally closer to the primary reinforcer

Freidman (2009) defines overshadowing as explaining how stronger conditioned stimuli (CS) overshadow weaker ones.

This is especially relevant in:

• Field tests

• Gundog work

• Any context where dogs must ignore handler body cues

If dogs begin responding to hand movement, treat pouch handling, whistle handling, or pocket movement instead of the intended cue, behavioural precision deteriorates (Friedman, 2009).

7. Why We Vary Reinforcement Delivery

This is exactly why we:

• Deliver food from different hands

• Use different locations (hand, table, pouch)

• Keep the marker clean and consistent

The goal is: Listen to the cue, not watch the handler (Pryor, 1999; Friedman, 2010).

By varying everything except the marker, we prevent any single movement from becoming a discriminative stimulus. Within every big ABC, there are always smaller ABC’s happening underneath.

Dogs are always learning, even when we don’t intend them to (Friedman, 2009).

Awareness of these layers allows us to:

• Use markers more cleanly

• Avoid accidental cueing

• Train with greater precision and clarity

• Train thoughtfully, because behaviour is never just one behaviour.

References

Friedman, S. G. (2009). What’s wrong with this picture? Effectiveness is not enough. Journal of Applied Companion Animal Behaviour, 1(1), 1–14.

Friedman, S. G. (2010). Behaviour analysis and learning. In S. G. Friedman (Ed.), Living and learning with animals. Behaviour Works.

Pavlov, I. P. (1927). Conditioned reflexes: An investigation of the physiological activity of the cerebral cortex. Oxford University Press.

Pryor, K. (1999). Don’t shoot the dog!: The new art of teaching and training.