Anger is not the same as fear. Both can lead to aggression, which is why the two emotions are often confused. But in fact they are readily distinguishable, based on the dog’s body-language.
Fear arises when the dog’s brain identifies potentially damaging situations that are outside its control; anger occurs when the dog’s expectations of the world are threatened. For example, dogs that are very attached to what they perceive as their territory will become angry when another dog (especially one of the same sex) intrudes into that territory. An angry dog, much like a fearful dog, will probably growl and bare its teeth, but these are primarily signals of intent and only secondarily expressions of emotion. It is easy to tell the difference between a fearful dog and an angry dog. The fearful dog will obviously be trying to escape, with everything from its ears to the corners of its mouth pulled backwards, and, if given the opportunity, it will most likely actually run away. The angry dog will be stiffened and poised to move forwards to counter the threat.
Anger, like all emotions, is an evolved survival mechanism, but also one that has been radically altered by domestication. A wolf that never defended its food or resting space from other wolves would not live for very long in the wild. However, the capacity to feel and express anger is less of an asset to domestic dogs, whose survival is crucially dependent on their owners’ goodwill, rather than on competition with others of their own kind. Indeed, domestication has raised the dog’s threshold for anger to the point where most dogs rarely become angry.
Dog trainers who still regard dominance as the key motivator for dog behaviour tend to explain most aggressive behaviour as driven by anger, specifically anger arising from the dog’s perception that its ‘status’ in the household has been challenged. This notion is almost certainly based upon a misinterpretation of what actually motivates most dogs. However, it would be irresponsible to insist that dogs never become angry, that they never try to assert themselves over other dogs, or challenge people who they think are trying to deny them something they value highly. For example, some dogs are highly territorial and will bark when their territory is invaded to show that they are angry at the intrusion. Among wild animals, ignoring such a threat would lead to actual aggression; the combined effects of domestication and training make this much less likely to occur in domestic dogs.
Although dogs are much less reactive than wolves, they still need to be taught emotional control, so that they can coexist peacefully alongside people and other dogs. In the wild, one of the crucial lessons mothers teach their offspring is to inhibit their bite: puppies’ teeth cannot do much damage, but it is essential that they learn to control the amount of force they apply when biting, so that they do not hurt their littermates while playing. Otherwise a full-scale fight could ensue. Moreover, once they have their adult teeth, uninhibited biting can cause serious injury. In the same way that they can learn to control their biting, an expression of anger, so dogs can learn to control anger itself. A dog that is never taught the consequences of its expressions of anger has the potential to become at least a nuisance, and at worst a danger to society and to itself. Dogs need to be taught boundaries, and by this I mean emotional even more than physical boundaries; permissiveness, allowing the dog to do as it pleases, is not humane. In nature, such behaviour would quickly be met by either aggression or avoidance, neither of which promotes survival in a social species. In human society, dogs cannot afford such trial and error, which ultimately leads to the pound or to euthanasia.
There is a very small minority of dogs that occasionally become aggressive without displaying any signs of fear or anger. It is often unclear whether such dogs are true ‘psychopaths’, whose emotions are abnormal, or whether they are simply able to inhibit the normal signals that would otherwise disclose their intentions. Such dogs are valued in the small sections of society where dogs are primarily used as weapons, but they are otherwise unsuited to life alongside humanity. (This is not to say that all ‘fighting dogs’ are psychopaths; many have been trained to become instantly aggressive on command, behaviour that is therefore potentially reversible.)
Such unannounced aggressive tendencies should not be confused with the so-called ‘aggression’ that, in the wolf, is an essential component of predatory behaviour. A dog that kills a sheep may casually be referred to as ‘aggressive’, but it is highly unlikely that the dog was frightened of the sheep or perceived it as a rival; rather, it was simply, if unacceptably, obeying the instinct to hunt. Motivationally, predatory ‘aggression’ is quite distinct from aggression driven by anger or fear – for example, it is controlled by a completely different part of the hypothalamus, and if it has an emotional component, this is more likely to be positive than negative (predators should be motivated to find hunting ‘fun’, to ensure that they keep doing it).
The range of dogs’ negative emotions is thus largely dominated by anxiety and fear, with anger appearing more sporadically. Individual dogs vary greatly in terms of both how intensely they feel each of these emotions and, to an even greater extent, in what external events trigger them. All, especially fear, are powerful promoters of learning, and so if a situation provokes a particular emotion once, it is likely to do so again if repeated. Fear and anxiety are associated with obvious body-language, although the precise form in which this appears varies from dog to dog: some dogs have learned that the best way to reduce their emotional discomfort is to move away from the source, while others may in the past have been given little choice other than to confront the problem directly. Thus aggression (aggressive behaviour) may be associated with either fear or anger – or indeed with no emotion at all, as in predatory ‘aggression’.
The physiological basis for positive emotions is less well understood than for fear, anxiety and anger (mainly because in human medicine it is much more important to characterize and treat the latter emotions, which are involved in many psychiatric disorders). Nevertheless, research suggests that the limbic system (including the amygdalae and the hypothalamus) is again among the key structures, and that the neurohormone dopamine is also crucially involved. One brain region that is especially important for positive emotions is the nucleus accumbens, the brain’s ‘pleasure centre’, which is situated quite close to the amygdalae.
Happiness – joy – seems to radiate from the majority of dogs, much of the time. Happy dogs have relaxed, open faces, and bodies that wiggle from the shoulders backwards, including the tail, of course. (But note that the tail may also be wagged when the dog is unsure and in conflict.) A cynic might say that dogs are conning us, that they merely behave as if they were happy, because happy-looking dogs are more likely to be well looked after than grumpy dogs. But scientists now firmly believe that mammals such as dogs do experience happiness.
There are good evolutionary arguments for the existence of happiness as a modulator and stimulator of beneficial behaviour. At its most basic level, learning theory postulates that all behaviour needs to be rewarded if it is to be repeated. Hunger causes an animal to seek out food, and once it is found and eaten, hormones released from the gut reinforce the behaviour, making it more likely that the dog will seek out and eat that food again. However, if there is something wrong with the food, and it makes the dog sick, then other hormone systems trigger an aversion. The dog will be unlikely to eat that particular food again for a long time – and may even avoid the place where it found the food.9
These straightforward examples posit the presence of immediate reward or punishment to trigger learning. However, other equally important types of behaviour are not associated with any immediate reward, and therefore must be performed simply because they make the animal feel good – in other words, happy. In the autumn, squirrels bury nuts in the ground rather than eat them so that they will have stored food for the winter. It is unlikely that a squirrel in its first year of life has the foresight to know that (a) bad weather is coming, (b) there won’t be much food available then, and (c) if it buries food that is abundant now, that food will
still be nutritious in a few months’ time. More likely, evolution has shaped the squirrel, once it has satisfied its immediate hunger, to find burying food and memorizing its location rewarding in itself. In other words, this activity makes the squirrel happy. Likewise, biologists used to have trouble understanding what motivates play behaviour. In wild animals, play must promote survival; otherwise, evolution would select against it – a young animal that is playing out in the open is much more obvious to a predator than one sleeping in its den. However, the benefits of play do not usually become apparent until months later, when they emerge in the form of better social integration or more sophisticated hunting techniques (to name but two, which vary from one species to another). Again, the simplest explanation is that play is self-rewarding; in other words – it is fun! Not just fun to watch, play actually generates happiness in the participants. Indeed, play and happiness seem inextricably linked in dogs, consistent with the idea that they are wolves which never grew up. It can take very little to bring about happiness in a well-cared-for dog; for example, when a dog catches sight of a favourite toy and starts playing with it spontaneously, that impromptu activity will have been generated by the feeling of happiness that the dog recalls from the last time it played with that toy. Dogs are also presumably happy when they are with their owners, but the overriding emotion in this case will be love.
Love – that which biologists, nervous about being misunderstood, call ‘attachment’ – fuels the bond between dog and master or mistress. For a young wolf, a strong attachment to its parents is crucial to its survival. The parents have all the skills necessary to protect and nurture the young cub – while it is growing up the cub can pick up those skills for itself, simply by observing and imitating its parents, rather than having to learn each one by trial and error. If it leaves the family group too early, the chances of surviving long enough to become a parent are significantly reduced. It is difficult to see how such a strong and essential attachment could not be emotionally based, given the underlying physiological machinery. If we accept the probability that dogs derive much of their typical behaviour from the repertoire of the juvenile wolf, then it is logical that their emotions should be similarly derived. In short, there is a sound biological reason for supposing that dogs do actually love us, rather than just appearing to do so.
At the physiological level, love is distinct from other positive emotions in that it specifically involves the hormone oxytocin. Originally this hormone was believed to be solely a trigger for care of newborns by their mothers (that is, nurturant behaviour), but it is now thought to be involved in all kinds of attachment. In fact, dogs experience a surge of oxytocin during friendly interactions with people. It is widely believed that interaction with dogs is a good stress-buster for humans. The reverse is probably also true. In one study, researchers set up a series of friendly interactions between dogs and people, consisting of stroking and gentle play.10 In the course of playing, the dogs’ blood pressure dropped slightly, as expected, and the circulating levels of several hormones increased dramatically (specifically, oxytocin levels quintupled, and endorphins and dopamine doubled). Similar, though less dramatic, changes occurred in the people.
The remarkable thing about this strong physiological response is that it is triggered by contact with Homo sapiens, a different species. As noted earlier, dogs’ attachment to people is often more intense than attachment to individuals of their own species; dogs that become very upset when their owners go out are rarely comforted by the presence of other dogs. It is tempting to speculate that ‘one-man dogs’ may lack oxytocin, but so far no one has looked into this possibility. What is clear is that all dogs have been programmed by domestication to have intense emotional reactions towards people. This lies at the root of the ‘unconditional love’ that many owners describe and treasure in their dogs. Such intense feelings are not easily turned off, as attested by the high proportion of dogs that hate being left alone (as many as one in five, according to one of my surveys).
Dogs really do miss their owners when separated from them. Many dogs also seem to become much more emotionally fragile under these circumstances; for example, they react much more negatively to sudden shocks, such as the noise of fireworks going off. In this sense, the capacity for love that makes dogs such rewarding companions has a flipside: they find it difficult to cope without us. Since we humans have programmed in this vulnerability, it is our responsibility to ensure that our dogs do not suffer as a result.
Without love, the dog–owner bond would not function. Yet as we have seen it is such a powerful emotion in dogs that many become anxious whenever they guess that they are about to be parted from their owner, and then remain anxious until they are reunited. This frequently leads to behaviour that the owner finds unacceptable. In the past, such problematic behaviour was often dismissed as ‘wickedness’ on the dog’s part, but we now know that it is actually deeply seated in the emotions of love and anxiety.
Dogs often leave all too visible signs that they hate being left alone, although these can be misinterpreted by owners who do not appreciate just how attached to them their dogs really are. The veterinary profession usually refers to cases of dogs that misbehave when alone as separation anxiety, but since it is not clear that all such cases are primarily due to the emotional state of anxiety (some are due to the dog panicking when it has been startled by some external event), I prefer to use the term separation distress when describing the symptoms.
Separation distress can take a variety of forms, depending on the dog’s breed and personality. Manifestations include destructiveness (biting, chewing and scratching of furniture or other materials, often close to the place where its owner has most recently left the premises, and in some cases involving items bearing the owner’s scent), vocalization (barking, whining or howling) and elimination (urinating, defecating or vomiting). Rarer symptoms include such signs of chronic and unbearable stress as self-mutilation and repetitive pacing.
Separation distress
I first started researching separation problems more than a decade and a half ago in response to an ill-conceived study purporting to show that dogs that had been through rescue and rehoming were very likely to develop separation distress. This conclusion placed the responsibility for separation problems firmly at the door of the rehoming charities, leading to the suggestion that every dog that was rehomed should be given a course of anxiolytics (anti-anxiety drugs) to tide it over during its first few weeks in its new home. There was very little research to support this assertion at the time, apart from one investigation that showed that mongrels were more likely than dogs with pedigrees to have separation problems. Animal charities rehome far more mongrels than purebreds, so logically it must be their fault! In fact, subsequent research I did with colleagues including Emily Blackwell, Rachel Casey and Justine McPherson has detected that rehomed dogs do have a slightly increased risk of developing separation distress, but this can probably be accounted for by the large number of dogs that are relinquished by their owners because they cannot be left alone.
Indeed, pedigree dogs are far from immune to separation distress, as our first longitudinal study showed.11 We followed the development of seven litters of Labrador retrievers and five of border collies, forty puppies in all, from the time when they were eight weeks old (and still with their breeders) to eighteen months of age. I was expecting that a few of these dogs might dislike being left alone. To our surprise and amazement, well over half of the Labradors, and almost half the collies, showed some kind of separation distress lasting for more than a month, peaking at about one year of age.
Our survey opened our eyes to the real scope of the problem. Based on 676 interviews with dog owners, we found that 17 per cent of their dogs were currently showing signs of separation-induced distress, and that a further 18 per cent had done so in the past but had recovered, mostly without their owners seeking any specialist help. But many other dogs suffer from separation distress that is unrecognized
by their owners. In another study, Emily Blackwell recruited twenty owners who were certain that their dogs were happy to be left in the house while they went to work. She then filmed each dog when it was left alone. Three showed signs of separation distress (pacing, panting or whining) that their owners were completely unaware of. One case was so severe that we recommended an immediate clinical consultation. Since separation distress is, by definition, something that happens when no one is there, with hindsight it is not surprising that only its more obvious manifestations – chewing, elimination, barking or howling that is loud enough for the neighbours to object to – tend to come to the attention of owners. While the sample taken in this study was tiny, it does suggest that research solely based on the self-reporting of owners considerably underestimates of the real scope of the problem.
If we assume that approximately 20 per cent of dogs suffer from separation distress, then the implications across the entire dog population are truly staggering. Of an estimated 8 million dogs in the UK, our figures indicate that at any one time, more than one and a half million of these dogs are suffering in this way.12 And of the 70 million or more dogs in the United States it is possible that well over 10 million may be experiencing separation distress.13 This is happening now, today. Such numbers suggest a real and ongoing crisis for dogs – and a totally preventable one. Separation distress could be virtually eliminated if every young dog, before it is left alone for any length of time, were trained to expect that departures lead to reunions (see box – ‘Home Alone: Can Dogs Be Trained to Cope?’). Once established, it is much more difficult to cure.
In Defence of Dogs Page 21