I don’t know about you, but in almost every behaviour consultation, or even talking with someone at the park, I get asked ‘why’ their pet is doing something in particular.

Dog owners try to understand why their dog that they have poured all their love and attention into, is suddenly fearful, assuring me that they’ve never hit them. Others might blame abuse in a former home as explained by the rescue where they got their dog.

My own dog, who used to be confident and friendly with new people, barks at strangers and is uneasy around people she doesn’t know really well. The reasons why this behaviour occurs are complex (and I very likely don’t know some of the contributing factors to her behaviour, although I am aware of quite a few of them).

There are generally considered to be 4 explanations for ‘why’ in ethology, and these were first listed out in a paper by Niko Tinbergen in 1963 entitled ‘on the Aims and Methods of Ethology’. They have become known as ‘Tinbergen’s four questions’’

The 4 Whys are:

Ontogeny – how development and experience influence behaviour

Function- which was called survival value at the time; the consequence of the behaviour (can either be short-term or long-term)

Phylogeny – how genetics influence behaviour

Causation – what happens before the behaviour occurs

These factors are explained in more detail below, as well as examples of some of the science for each.

Phylogeny (or genetics)

Phylogeny looks at the evolution of behaviour, and how genetics influences behaviour. This could include things such as how breeds or even lines within a breed can influence behaviour, and this is an area which has increased in popularity lately due to the accessibility of genetic testing.

Phylogeny can explain why animals do certain things, for example it could explain, in part, why a Border collie or Australian shepherd runs around behind children, possibly nipping at their heels or trying to herd them. It could also explain why a Ragdoll cat may lie around the home being placid and quiet.

While we often expect certain individuals of a particular breed to behave a certain way, this isn’t always the case. It’s not uncommon to get a golden retriever who isn’t friendly and may show aggression towards other people or dogs, even though that breed is considered one that is friendly.

Study Examples

A study published in Animals in 2019 (Shouldice et al., 2019), looked at inherited behavioural traits of both labradoodles and goldendoodles compared to the breeds from which they are crossbred, or their parent breeds (ie labs or golden retrievers bred to poodles). The researchers used a questionnaire called C-BARQ (Canine Behavioral Assessment and Research Questionnaire) that is commonly used in behaviour research for dogs, where dog owners can complete an extensive questionnaire about the behaviour of their dog.

C-BARQ responses were used to compare behaviour, and both labradoodles and goldendoodles were found, for the most part, to have behaviour that fell between the two parent breeds. However, there were some differences found – goldendoodles showed much more dog-directed aggression than either parent breed, as well as showing high levels of dog-directed fear and stranger-directed fear.

A recent study in Science (Morrill et al., 2022), looked at a huge database of pet owner surveys about behaviour, as well as genetic testing from a subset of the dogs. They found that overall, breed explained 9% of individual animal behaviour. While this is a significant amount, it’s likely not enough if you’re looking for particular behavioral characteristics to go solely by breed. Some behavioral traits were more heritable, for example genetic variation was found to be responsible for 25% of variability in sociability, behaviour with toys, and response to direction and cues.  It’s important to consider that while the breed may have a general behavioral characteristic, any individual animal may have behavior and one or the other end of the spectrum for that trait.

Ontogeny (changes due to development)

Ontogeny relates to behavioral changes caused by experiences an animal may have had, good or bad. It can also be behaviour due to maturation and learning.

This could include things like experiences during the socialization period. This is a period where animals are primed to learn about new social experiences and (hopefully) decrease potential for the development of fear. Positive exposures to people, other animals, environments, noises, handling, and other situations is important. In dogs, this period of time is 3 to 12-16 weeks of age, and more information about this period can be found IN THIS POST.

Other experiences, such as positive punishment, interactions with other animals, and more, can affect their future behaviour. Experiences that influence behaviour aren’t solely negative, positive experiences can also influence future behaviour.

There has also been research (in many different species) looking at prenatal stress and its influence on behaviour and learning of animals, even as adults. Hormonal and neurotransmitter changes in the mother cause these changes in offspring, some of which can be helpful and others can negatively affect their future learning and behaviour.

Study Example

An example of this is a research paper that looked at age at castration in male dogs and the resulting behaviour problems later in life (McGreevy et al.,). This study again used the C-BARQ and the various behaviour categories associated with that questionnaire.

The researchers found an association between earlier neutering in male dogs, and therefore less exposure to sex hormones, with an increased level of fear in various situations as well as some aggression towards strangers. The authors state: “It is possible that, during the transition through puberty, sex hormones play a role in proofing dogs against fearfulness in later life”

The next two reasons for why an animal may be behaving in a particular way are ones that I personally feel are most important if you’re helping people with pet behaviour problems. They look at what happens before the behaviour is performed, and the consequences of that behaviour, two factors we deal with a lot.


There are two ways of looking at the function of a behaviour:

  1. The immediate consequences of the behaviour for an individual animal
    (As a basic example, eating dinner so that you are no longer hungry).

  2. The ultimate function, which is more of a population-level explanation and looks at how that behaviour helps the next generation or the future of that species. This also includes reproductive success, however in pets we control much of this.
    (As an example, an animal building a nest to ensure the survival of more of the following generation).

In animals that we care for, function can be very important as it can be responsible for what is encouraging or discouraging particular behaviours. When we’re training, either intentionally or unintentionally, we make use of the function of a behaviour by affecting what our pets get following a behaviour. This can be done deliberately through operant conditioning, but also simply from someone’s unintentional reaction or what happens following the behaviour without human input.

For example, if we reward a dog for coming when called fairly regularly, it makes them more likely to come the next time. Positive reinforcement at it’s finest.

The alternative is also possible, and we can accidentally be encouraging a behaviour. For example, if you have a dog that jumps on you in the morning to wake you up and you get up and feed them, you’re encouraging that behaviour. Your cat meows, and the function of that is to get you up to feed them.

In our domestic animals, and especially in those we typically have in our homes, the ultimate function, or reproductive success, is primarily controlled by people. We manage breeding, the environment in which the parents and offspring are kept, and many of the other factors that would influence the survival of the next generation.

Study Example

A research study looked at details of dyadic play between dogs, or play between two dogs to determine the function of play bows between dogs (Byosiere et al., 2016). Video of play bouts between dogs in a large enclosed outdoor area were observed and included interactions of two dogs together at one time. A total of 16 well-socialized dogs were used, one of which was an adolescent and the others adult dogs.

The authors wanted to determine the function of play bows and looked at 5 different hypotheses:

  1. Play bows serve to re-initiate play

  2. To clarify that behavior following the bow is playful in nature

  3. That the play bow position allows the dog to attack and escape their play partner

  4. The play bows help to synchronize play behavior

  5. That play bows are a visual signal for another dog

By looking at the behavior of both dogs prior to a play bow, during the bow, and following the bow, they were able to determine that play bows were associated with the re-initiation of play (with bowers and partners being more active after the bow), that behavior was more synchronized after the bow (bowers and partners performed higher proportions of synchronous behaviors after the play bow than before), and they served as a visual signals (almost all incidents occurred when the dogs were within one another’s visual field).


When considering the causation of a behaviour, we’re looking at the internal and external stimuli that elicit a behaviour. This can include a wide range of things that are happening inside and around the animal, such as the feelings they might be experiencing, or a sudden environmental change like a loud noise in the room next door or appearance of a stranger.

In behaviour modification, in training, and in management, this is one we look at A LOT.

As an example, looking at the external factors could be important in something like separation anxiety. When working with pets that experience anxiety when people leave the home, one of the common steps involves figuring out all of the various departure cues that a dog might be taking in that lets them know their people are going to be leaving the house.

Another example is looking at the internal factors that cause your pet to act the way they do. This could include a variety of internal factors, such as hormone levels, or even the emotional component associated with a behaviour. In many cases of dogs exhibiting aggression towards people or other dogs, fear or anxiety might be contributing as an internal factor associated with that behaviour. Motivation is also often closely tied to causation.

Causation is one of the primary reasons why it is suggested that an animal have an exam by their veterinarian prior to working on behaviour problems to ensure there are no medical reasons for the behaviour prior to beginning a training and behaviour modification plan.

Study Example

An example of this is a study that looked at noise sensitivities in dogs that had musculoskeletal pain (Lopes Fagundes et al., 2018). In this study they looked at cases of noise phobias that have been referred to clinical animal behaviourists, some of which had clinical cases of musculoskeletal pain and others that did not.

They found that the dogs that had noise phobias as well as a pain component developed the noise phobias on average 4 years later than the other cases, the noise phobia was more likely to be generalized to environment as well as avoiding other dogs, and the noise phobias were resolved with the treatment of the underlying pain.

This study shows that, while not all noise phobias are caused by pain, that some cases are and resolving the pain can help to eliminate the behaviour problem.

How do I use this information?

If you work in training and behaviour modification, you will, or likely do, reach for this information frequently. I personally find it helpful when talking to clients to explain behaviour they’re seeing, especially when I get the question about why an animal is doing something.

It can be used as reassurance that what they’ve done with their dog up to this point is not solely responsible for the behaviour problems they’re experiencing, that they haven’t horribly or irreversibly done something wrong with their dog or cat. I’ve also used this information for almost the opposite reason, when people may be convinced that their dog experienced abuse in the past due to the fearful behaviour they’re seeing, and are directing anger towards a previous owner.

I find that going through this and explaining the many reasons why an animal may be behaving the way they are helps to put things into perspective and understand that there are factors that can be changed, ones that can be managed, and ones that can’t be changed. These all make up the dog they have, and also helps when setting expectations for change.

If you’d like a less technical version of this to share with clients, one can be found on the Landmark Behaviour Blog that is written for pet owners.


McGreevy PD, Wilson B, Starling MJ, Serpell JA. 2018. Behavioural risks in male dogs with minimal lifetime exposure to gonadal hormones may complicate population-control benefits of desexing. PLoS ONE 13(5): e0196284.

Morrill, K., Hekman, J., Li, X., McClure, J., Logan, B., Goodman, L., Gao, M., Dong, Y., Alonso, M., Carmichael, E., Snyder-Mackler, N., Alonso, J., Noh, H. J., Johnson, J., Koltookian, M., Lieu, C., Megquier, K., Swofford, R., Turner-Maier, J., Karlsson, E. K. 2022. Ancestry-inclusive dog genomics challenges popular breed stereotypes. Science, 376:6592.

Souldice, VL., Edwards, AM, Serpell, JA, Niel, L, Robinson, JAB. 2019. Expression of behavioural traits in Goldendoodles and Labradoodles. Animals 9:1162.

Byosiere, S.-E., Espinosa, J., & Smuts, B. 2016. Investigating the function of play bows in adult pet dogs (Canis lupus familiaris). Behavioural Processes, 125, 106–113.

Lopes Fagundes AL, Hewison L, McPeake KJ, Zulch H and Mills DS. 2018. Noise sensitivities in dogs: An exploration of signs in dogs with and without musculoskeletal pain using qualitative content analysis. Frontiers in Veterinary Science. 5:17.