One of the great advantages of a scientific approach to behaviour is that we can define certain words to mean certain things. Then everyone knows what everyone else is talking about. Makes perfect sense - in theory. As Thomas Huxley put it, "The great tragedy of science - the slaying of a beautiful hypothesis by an ugly fact." The ugly fact in this case being that not everyone does use the terms as they are defined. Otherwise carefully-defined terms are being used in all sorts of contexts - sometimes through ignorance, sometimes because it suits a trainer's purpose to sound more benign, however much of a mismatch there is between what she says and what she does.
Perhaps the most abused term is positive reinforcement. Ever since behaviourists started to point out that positive reinforcement would be more beneficial to horses than more conventional training, people have gone out of their way to redefine a release of pressure as a reward, as something positive because the horse wants it. It doesn't matter that in behavioural terms, the "negative" in "negative reinforcement" simply means "removing", we are all still highly conditioned to the emotive connotations of the word so we want to pretend we don't do it. Just because the horse wants and benefits from the removal of the pressure, we have not left the domain of negative reinforcement: "an increase in the likelihood that a behaviour will reoccur via removal of an aversive stimulus" is how negative reinforcement is defined, regardless of how mild the aversive stimulus.
Interestingly, reward-based training also seems to be in doubt. As the use of positive reinforcement with horses has become more widespread, typically (although not always) through clicker training, we are starting to build up a picture of what the horse might experience. Just because treats are used in the training, does not necessarily mean that the horse is having a positive experience. There are many examples of horses being trained with clicker training where the rewards are combined with negative reinforcement, where the horse is frustrated, fearful or in pain, where the horse is under such highly conditioned control that there is little remaining positive. While we define positive reinforcement as "an increase in the likelihood that a behaviour will reoccur via addition of a pleasant stimulus", it is often debatable whether the reward is the true reason for the change in behaviour. The presence of treats does not always compensate for the degree of pressure (physical or mental) also experienced by the horse and the change in behaviour can often be attributed to other means.
To be fair, this discussion of operant conditioning is not the topic of choice of many horse owners, who just want to enjoy doing whatever equestrianism they do. But perhaps we should expect more of people whose careers depend on teaching people about behaviour. Horse trainers, riding instructors, academic researchers..... Yes, really, I did say "academic researchers". We seem to have gone full-circle and now the definitions which emerged from academia originally are not necessarily the ones in active practical use today. Why is this? Could it be that, yet again, there is a lack of congruence between the theory and what people find themselves teaching in practice?
Take the term "habituation". By this we mean that an animal's response to a stimulus gradually diminishes through many repetitions and the animal "getting used to" the stimulus. So horses living near a railway line, and who are able to escape sufficiently far away that they do not feel afraid, will flee progressively shorter distances and habituate to passing trains. This ability to escape is crucial for habituation to occur. Without the means to escape, a horse is being forced to confront his fear and we find ourselves in the realm of flooding. And it doesn't take much delving into behavioural science to learn that flooding is damaging and we don't want to do it. Oh no, people go to all sorts of means to redefine their flooding techniques as a pleasant-sounding euphemism. Conventionally we would "show the horse who was boss", as though domination of the horse's expression of fear was crucial to our self-esteem. In so-called "natural horsemanship" trainers tend to talk about "getting effective" or "raising their energy", sometimes invoking martial arts or other distractions. In some academic circles it seems that people invoke habituation.
One example I saw was the horse "being habituated to saddle and rider", with the horse looking pretty unhappy about the whole experience. There was no escape for the horse. There was no repetition. It was just a rider sitting it out while the horse "got used to it". Getting used to it in the sense of giving in. Otherwise known as flooding. Another example I heard was where habituation supposedly involved presenting a scary object and only removing it when the horse remained immobile - at best this is negative reinforcement and would very easily become flooding. Either way, this is not habituation, which is not something that we can really do to another being. While I think it is great that academics are applying theory in the "real world" a lot more than when they remained in laboratories, there still seems to be a big discrepancy between the language used and their actions. It is bad enough teaching the general public flooding techniques, but much worse if we call them by different names.
As if this were not of sufficient concern, we also have the subject of overshadowing. In every day language, this simply means that if two conditioned stimuli are presented simultaneously, one will be more salient than the other. But in behavioural science the definition is a little more specific. The two conditioned stimuli should first be associated independently with the same unconditioned stimulus and conditioned response. So as a simple example, we might call our horse in from the field for his supper and he comes to the gate. Or we might rattle a feed bucket and he also comes to the gate for supper. But if we simultaneously call and rattle the bucket, it is likely that one of the stimuli will be more relevant to the horse and so it will overshadow the other. CS1 = calling, CS2 = rattling bucket, US = food, CR = seeking food. So far so good, just simple, classically conditioned associations causing the horse to behave in a certain way.
More recently, some trainers have complicated this by introducing an aversive training technique to be the more salient stimulus when a horse is being subjected to a task he finds unpleasant, such as standing still for clipping, vet procedure etc. We do indeed have two stimuli, one more salient than the other but we now have a whole mixture of stuff going on. Firstly it is not technically overshadowing because the two stimuli elicit different responses - e.g. fear of unpleasant task vs. standing still due to aversive training technique. Secondly, if you force a horse to stand still in the presence of something he finds frightening then you are resorting to flooding. If you implement this by means of an even more aversive technique then it remains flooding and doesn't suddenly change to the more acceptable-sounding overshadowing. Just because we can assign a behavioural term to a technique, doesn't mean it is a) correct or b) ethical to use that technique. Goodness knows what is going through the horse's mind when he has a "choice" of flooding options.
So why does any of this matter? Is concern about term-abuse merely a spot of semantic gymnastics for the over-educated, or does it constitute a welfare issue? Science and the language of science evolve, is this any different?
Like it or not, conventional horse training makes use of negative reinforcement at best and often positive punishment. Despite the terminology, the use of mild aversives do not have to be damaging to the horse, but it is important to be aware of what we are using. That way we can be sure that the aversive stimuli we use can be kept at a low level and can concentrate on using good timing of our releases. If we believe that what we are doing is positive then we are less concerned about releasing because there is supposedly no pressure to release. We are less concerned about keeping our aversive stimuli mild because we believe we are not using them.
Similarly when "experts" tell us that we are using the processes of habituation or overshadowing to change a horse's behaviour, we are not concerned that we are over-exposing the horse to a prolonged source of fear or discomfort, even though that may well be the case. I've found it interesting listening to proponents of various natural horsemanship methods who are all opposed to flooding when it takes place via somebody else's method, but oblivious and/or in denial that it is used equally by their own favourite "guru". It seems that some academics/trainers are not immune to this either.
If we are using flooding persistently then we are crossing into the territory of major welfare implications. The horse will find that nothing he does can change the situation for the better so he will give up. He may develop one or more conflict and/or abnormal behaviours. The suppression may generalise to other aspects of the horse's life and approach something that could be described as learnt helplessness. The long-term stress may have physical implications such as developing ulcers or a tense musculature and biomechanics.
As professional behaviourists and/or trainers helping horse-owners, we have a duty of care towards our clients. They believe we know the theory and how to apply it. They are entrusting us with the welfare of their horses. If we abuse that trust then we are doing horses a great dis-service. We are setting back the science of behaviour and its application and are effectively giving permission to anyone to use flooding techniques without understanding the consequences for the horse. It is hard enough propagating an informed message about behaviour and training without us working against ourselves.
There is a free on-line glossary of behavioural definitions and practical examples at http://www.ebta.co.uk/faq-definitions.html and I have written most of it. In the interests of not being hypocritical, I would welcome any corrections if you feel they are warranted
Oh, and if you enjoyed this article then there it inspired a further article by Mat Ward which can be found at the following link: http://www.apbc.org.uk/articles/overshadowing-habituation-positive-reinforcement-in-horse-training