Trainers are often reluctant to keep negative reinforcement (Sr-) in their tool kits, and for good reason. There is a long history in animal training of applying and removing aversive stimuli to teach new behaviors. Trainers understand that aversive training methods come with potential fallout, primarily with respect to the emotional responses of the animals.
When used in common training procedures, an aversive stimulus is applied, and then the animal must do something to “turn off” the aversive stimulus. For example, a trainer may pull up on the leash (an event that serves as an antecedent or cue), wait for the dog to sit, and once sitting (desired behavior), release the tension in the leash on the dog’s neck (an event that serves as a consequence, specifically, a negative reinforcer). Negative reinforcement used in this way can be effective in getting a dog to sit, but it creates a learner that is working to avoid aversive outcomes, not one that is working toward certain desirable outcomes.
Negative reinforcement occurs naturally in the environment. For example, if a dog is frightened of strangers approaching, but is prevented from escaping, the dog may behave aggressively because he has learned that strangers tend to retreat under these conditions. So, the stranger approaches (aversive antecedent stimulus), the dog lunges/barks/snaps (these behaviors are labeled as aggression), and the stranger leaves (negative reinforcer). The aggressive behaviors are more likely to occur because they produce the outcome the animal is working for—putting distance between themselves and the stranger.
Though both of these new behaviors have been created through negative reinforcement, in one of these scenarios the reinforcer is artificially introduced by the trainer (pulling on the leash), while the other is formed via natural reinforcers in the environment (the stranger approaching the dog). This distinction becomes very important when you want to change these behaviors (or any existing behavior). Understanding the existing contingencies that have shaped this behavior initially is to recognize the most valuable reinforcer for that learner in that environment. For example, the dog aggresses to put distance between themselves and the stranger. The increased distance from the stranger in this context is what the dog is working for, and therefore is the maintaining reinforcer for the aggressive behavior.
One of the best ways to deal with aggression is to train alternative behaviors using differential reinforcement so that preferred behaviors are established to replace undesirable behaviors, emotionality is minimized, and, importantly, the original aversive stimulus is ultimately conditioned as a positive reinforcer. A humane way to use negative reinforcement is in a DRA procedure geared toward helping the animal create a positive association with the aversive stimulus that resulted in his problem behavior being negatively reinforced in the first place. Using the aggression towards strangers example, the discriminative stimulus is a stranger approaching. The DRA portion involves the stranger walking away (i.e. delivering the reinforcer) when the dog performs a different, safer behavior instead of going away when the dog behaves aggressively. The alternative (safer) behavior is now reinforced by the increasing distance of the stranger, (the maintaining reinforcer) instead of the aggressive behavior. As a result, the aggressive behavior diminishes and the appropriate behavior increases, all in the presence of the aversive stimulus.
In summary, the use of negative reinforcement has been successfully used as a rehabilitation procedure when a behavior entered the learner’s repertoire as a result of negative reinforcement in the natural environment.[i], [ii], [iii] When teaching a behavior that is new to the learner, or a known behavior under new stimulus conditions (e.g. a dog learning to sit upon hearing the word “Sit”), positive reinforcement is a more reliable tool that is likely to create a learner that is working to attain a desirable outcome, rather than working to avoid or escape aversive stimuli.
discussion around negative reinforcement has been polarizing in the animal
training world. There are negative reinforcement based techniques that can be
detrimental to the animal’s wellbeing and behavior and to the human handler.
However, when used to replace functional behaviors learned through negative reinforcement,
it can be a humane approach to resolving challenging behavior problems.
[i] Snider, K. (2007, December) A Constructional Canine Aggression Treatment: Using a Negative Reinforcement Shaping Procedure With Dogs in Home and Community Settings. https://digital.library.unt.edu/ark:/67531/metadc5120/
[ii] Rentfro, A. (2012, May) Fearful to Friendly (F2F): a Constructional Fear Treatment for Domestic Cats Using a Negative Reinforcement Shaping Procedure in a Home Setting. https://digital.library.unt.edu/search/?q=Angela+rentfro&t=fulltext&sort=
[iii] Snider, K. (2018) Turning Fierce Dogs Friendly: Turning Fierce Dogs Friendly: Using Constructional Aggression Treatment to Rehabilitate Aggressive and Reactive Dogs, Fox Chapel, PA, Companion House Books.