No other type of pet currently attracts such huge attention from scientists as the dog. Research is particularly focused in this regard on the two major areas of “Learning, cognition and intelligence of dogs” and “Interaction and bonding between dogs and humans”. Some of the more recent research results on the topic of “interaction and bonding” are presented in the following.

It is not only dog owners that are interested in what their dog thinks of them and whether he likes them – it is also a riveting topic for scientists. Is the “love” mutual, is the dog just as keen on forming a relationship with a human being as the other way round? Or is it more wishful thinking on the part of humans that our dogs “love” us? And if the bond with humans is important to dogs – for what reason? Because we give them food and a dry place to sleep – or is there more to it?

The structure of and changes in relationships or the “attachment” between people has been researched intensively since the 1940’s. The resulting attachment theory, developed by Bowlby, Robertson und Ainsworth, proceeds from the premise that humans have an innate need to establish close relationships with other people and that they gain the confidence from these close relationships to explore the world, for example. Too much distance from the attachment figure causes stress in young children, in particular. Children who grow up in a “secure attachment” are more socially competent, more imaginative, more stress-tolerant, better able to concentrate and, all in all, more self-confident than children who have not experienced this secure bond. This is also referred to as the “secure base” or “safe haven” effect.
James Serpell, an American behavioural scientist, describes the relationship between dogs and humans as an asymmetrical relationship based on dependence, similar to that between parents and young children. Based on this assumption, Gacsi and her colleagues from the ethological research group at the University of Budapest set out a few years ago to observe dogs and their owners in a simple test. They observed the behaviour of dogs and measured their heartbeat during two encounters with a menacing stranger: on one occasion, the dog was alone in the room and, on the other occasion, the owner was present. All of the dogs reacted to the menacing stranger with a higher pulse rate and (in individual cases, differently modulated) stress behaviour. In the presence of the owner, however, this reaction was distinctly less intensive than when the dog was alone. The sequence of the events also played a part. In one group, the dogs were alone when first confronted with the stranger, with the encounter in the presence of the owner ensuing subsequently; this sequence was reversed in the other group.
When the dog first faced the menacing stranger alone and then encountered him again in the presence of the owner afterwards, the dog’s heart rate and behaviour did display differing intensity (the owner’s presence provided security) – but the dogs nevertheless also displayed a detectable increase in heart rate and stress behaviour in the presence of the owner. When the dog first encountered the stranger in the presence of the owner and then subsequently alone, their stress behaviour and pulse both remained significantly lower. This was explained by the researchers as being due to a learning effect, i.e. the owner has some kind of buffer function that enables the dog to confront a recurring stress factor in a more relaxed way even in the absence of the owner. An interesting fact in all cases was that the owners remained passive, i.e. they were “just there” without explicitly occupying themselves with their dog.
The general conclusion drawn by the researchers from these and other similar experiments is that effects arise in the “dog-owner” relationship which are comparable to those in the “parent-child” relationship, i.e. the “secure base effect” also exists for dogs (Gacsi et al., 2013). Horn et al also arrived at the same result in 2013 when they tested dogs in problem situations with different human subjects. The dogs tries to solve the task for longer and more actively in the presence of the owner that when an unfamiliar person was present.

How has this come about? Wolves in prehistoric times certainly did not search actively for a “safe haven” or only become attached to humans for that reason. “Security” in the broadest sense has, however, played a role for the development of this unique coexistence on Earth between animals and humans. According to Coppinger & Coppinger and other researchers, the prehistoric wolves in the late Stone Age ventured closer to human dwellings because they were able to find food there and shelter from their enemies. In the course of a few generations, this had developed into a symbiosis in which each was beneficial to the other. The prehistoric wolves became increasingly less timid in their contact with humans and slowly but surely developed into the original dogs. By the time of the Neolithic age at the latest (around 13000 BC), they had moved so far away from the wolf in anatomical terms that they have been referred to as domestic dogs ever since (Drake et al., 2015).

Certain characteristics of the prehistoric wolves, such as their willingness to cooperate and their tolerance towards (even unfriendly) conspecifics, favoured such a development. Range et al (2015), for example, do not see it in terms of this tolerance and willingness to cooperate only developing during domestication but, rather, actually see it as a crucial factor, together with differentiated intraspecific social behaviour, for the emergence of today’s domestic dog. Other elements like the benefits of human pointing gestures and the ability to “read” human expressions seem to have been more of an effect than the basis of domestication.
Dogs have a great willingness to pay attention to human gestures. This is not surprising in fundamental terms given that paying attention to the signals of a social partner is a MUST for relaxed coexistence and cooperation within the social group. Or for the successful solving of tasks such as capturing larger prey that is able to defend itself. In the course of coexisting with humans – as a consequence of domestication – dogs have extended these abilities to humans and learnt to make use of the signals from people for their own benefit. Dogs look for eye contact with people more intensively and react to nodding of the head or pointing gestures better than wolves, as shown by numerous studies over the past few years (summarised, for example, by D’Aniello et al., 2015). Just as long, however, as it does not concern food. Once food comes into play, wolves socialised to humans make use of the latter’s pointing gestures better than dogs do. In dogs, the degree of socialisation to people also appears to play an important role for this form of cooperation, as recently demonstrated by Lazarowski & Dorman (2015). They compare dogs from a laboratory dog population (little contact with humans) with privately owned dogs. In pointing gesture tests, the privately owned dogs performed better than the laboratory dogs.

How intensively gestures or other signals are made use of in unknown situations or for unfamiliar tasks also depends, however, just like general attention towards the owner, on the level of training of the dogs. Intensively trained dogs (versatility trials, agility, rescue dog work, etc.) look at their owners more often during “normal” walks than their untrained counterparts do. If the trained dogs are confronted with problems (searches, detours or other tasks), they occupy themselves more actively, intensively and independently with solving the problem and are also more successful in this regard than untrained dogs. The dogs that had not been trained looked for contact with their owners more frequently, as a kind of reassurance, while the intensively trained animals worked on solving the problem in a more independent manner. In what is referred to as the “impossible task paradigm” (Miklosi et al., 2003; Marschall-Pescini et al., 2009, D’Aniello, 2015), things were different. In this experiment, the dogs learned how to get food out of a box. Afterwards, the box was positioned in such a way that the dogs could see it but were not able to reach it. This meant that the problem-solving strategies learnt previously were useless. During this very frustrating experience, intensively trained dogs searched for eye contact with the owner more intensively and also maintained it for longer than untrained dogs.

But every coin has two sides. As positive as it is, in principle, with regard to successful training for a dog to look at a person often and make use of the person’s signals for its own work... it does, of course, also pose the risk of errors in more detailed work. Lit et al showed in 2011 that the so-called “Clever Hans effect” should not be underestimated in work with drug and explosion detection dogs. The dog handler’s knowledge or lack of knowledge about the presence of odorous substances in the search area had a major influence on the “work performance” of the respective dogs.

Monitoring the Clever Hans effect in training and minimising it as far as possible is certainly one of the major challenges in dog training. Dogs are predestined for working together with people on account of the willingness to cooperate and tolerance previously mentioned. Bräuer et al (2013) were able to show that dogs are motivated to help people with difficult tasks like opening a door – within the limits of their anatomical possibilities, of course. The person tried several times in vain to reach a key to open the door. The dog was able to open the door easily by pressing its nose against a button. The dogs “helped” the people when the person pointed directly at the button concerned or when the person looked somewhat “helplessly” between the door and the hiding place for the key and spoke to the dog at the same time. The identity of the “desperate” person did not play a decisive role in this respect. The dogs helped their owners as well as an unknown experimenter.

It has been known for a long time that dogs can coordinate their behaviour with that of a canine colleague in order to solve a joint task and, if necessary, also wait until the partner is ready. Ostojic and Clayton (2014) were able to show in a simple “rope trick experiment” that this willingness to cooperate is also displayed vis-à-vis humans. Food could only be got out of a box if two individuals worked together, both pulling on “their” rope at the same time. The dog also had to wait for the human partner to “sort out” his rope. No individual could solve the task alone on account of the ropes being too far apart for a dog to take both of them together in its mouth and pull on them. In the rope trick experiment, the dogs worked together successfully with an experimenter not known to them. However, when dogs were set multiple tasks/problems one after the other and presented with different human partners for this purpose, the animals displayed a clear preference, ideally wanting to work with their respective owner (Kerepesi et al., 2015).

At the beginning, the question was asked whether the “love” between dogs and humans is mutual, whether attachment to people is important to dogs and, if so, why. As shown in the preceding paragraphs, people do indeed appear to play an important role for dogs as social or attachment partners and not only because of the human being a can opener. If that was the case, dogs should then be expected to cooperate with any stranger who has shown them just once that it is worthwhile by dangling a piece of food in front of their nose. The studies conducted by Kerepesi et al, in particular, have shown that this is not the case. Like people, dogs also have preferred attachment partners – and they prefer, at least where only one dog is kept, two legs to four. It has not yet been examined whether dogs do actually prefer a canine to a human attachment partner in a household with more than one dog.
In a “classic jealousy test for 6-month old children” modified specifically for dogs, the animals displayed reactions to the “misbehaviour” of their owners comparable to those shown by children towards their parents (Harris & Prouvost, 2014). In this test, the owners occupied themselves intensively with a book, a hollowed-out pumpkin or a large toy dog. The dogs displayed differences in behaviour depending on the object concerned. Occupation with the toy dog aroused greater excitement, e.g. pushing the object away, threatening behaviour towards the object, snapping at the object, than being occupied with the pumpkin or the book. The researchers discuss jealousy as being an old emotion in terms of evolution which has major biological value for social animals, at least. Accordingly, it is found in various species in the animal kingdom. However, the dog is the only species of animal whose individuals display jealousy in relation to members of a different species (humans) in a recognisable and differentiated manner. The researchers see this as evidence of a close emotional bond between dogs and humans of a strongly pronounced bidirectional nature; ... and as further evidence of the high socio-cognitive skills of dogs.

In the context of bidirectional attachment and emotions, it is certainly also interesting to take a look at the other end of the leash. This is precisely what Stoeckel et al (2014) did when they looked at activity patterns of human brains in fMRI scans. The subjects were mothers with at least one child and one dog. The women were presented with pictures of their own child and a strange child as well as of their own dog and a strange dog. The areas in the brain responsible for the forming of emotions, recognition of rewards, friendship and social cognition are well known. In the experiment, it was examined whether different activities would be measurable in these areas depending on what photo was observed. This was indeed the case. Not only did the viewing of unknown children or unknown dogs leave the mothers more or less “emotionally cold”... the sight of their own dogs triggered emotions and excitement that were comparable to and only slightly less intense than seeing their own children.

So it would appear that the “love” between dogs and humans is mutual. However, it is rather difficult to measure and define the extent of this in specific terms. Rehn et al attempted to do this in 2014. On the basis of a standardised questionnaire, they evaluated how intensive the owner’s emotional attachment was to his or her dog. They also examined the intensity of the attachment on the part of the dog by observing its behaviour on being separated from and then being reunited with its owner. During the separation phase, the dog was also confronted with a stranger. Based on their results, the researchers came to the conclusion that the intensity of the emotional attachment on the part of the person is not causally related to a strong attachment on the part of the dog. As they conducted their study with just 22 dog-owner teams, however, the researchers themselves said that more studies were needed with more subjects and that more differentiated analysis was required with regard to what generally happens in the situation of dog and owner living together, how their everyday lives are structured, etc. Payne et al (2015) pointed out in parallel that human characteristics such as bonding affinity, friendliness and a generally positive attitude to dogs play an important part in relation to the attachment and the emotions that the dog displays to its owner.

It is also interesting to examine whether the type of friendly interaction with a human could play a role for the dog. The behaviour of dogs was observed by Feuerbach and Wynne (2015) in two different interactions: in one situation, kind words were spoken by the person without any physical contact while, in the other situation, the dogs were stroked intensively by the people without speaking. These people were either the owner or a stranger in each case; in addition, both privately owned dogs as well as dogs from animal shelters without attachment partners were observed and the dogs were given the choice to opt for one of the two types of interaction. All of the dogs, including those from the animal shelter, clearly preferred the stroking to the friendly words. It also seemed that they could not get enough of the stroking. Even with a stranger, the dogs remained in the interaction for the full five minutes that each situation lasted while they quickly lost interest in only being spoken to and walked away.

This has been a brief overview of some of the more recent research results on the topic of interaction and attachment between dogs and humans. There is definitely still room for more research on this subject and it will be interesting to see what new findings and knowledge surface over the next few years. On the other hand, these results are certainly sufficient for every dog owner to confirm what he/she has always known: dogs enrich our lives and, if we do things right, we also enrich theirs. Or, to use the words of Udell and Wynne (2008): “perhaps we should stop thinking about it and simply love our dogs”.

Dr Barbara Schöning