From our daily experience we know that most of the time cats and dogs are involved in fights rather than in expressions of affection. Is there an evolutionary basis(justification) for this?

Why would two species of animals fight each other (apparently for no reason) wasting their precious energy?

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    My experience is that dogs will be involved in chasing cats, and that the participation from the cat's point of view is highly involuntary. Commented May 11, 2011 at 18:34
  • The most obvious would be that they were conflicting over food resources, both being predators - both evolutionary-wise, and in current conditions.
    – user5341
    Commented May 11, 2011 at 19:02
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    This post NEEDS THIS ;-)
    – Sklivvz
    Commented May 12, 2011 at 8:07
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    I personally don't buy the premise that cats and dogs fighting is inherent or unique just because they are cats and dogs. In my experience, dogs tend to chase after any animal it doesn't recognize, not just cats. I think the reason people associate cats/dogs fighting is because by and large, they are the most popular pets and the most common interactions between animals that people see. Once cats and dogs get to know each other they can be quite affectionate towards the other.
    – Dunk
    Commented Oct 24, 2012 at 20:14
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    I'm not seeing how, in its current phrasing, this is a skeptical question. Commented Oct 26, 2012 at 3:44

3 Answers 3


You Should not Expect a Just-So Story

To my eyes, the question reeks of adaptationism: the attempt to explain what we see (cats and dogs, or otherwise) exclusively in terms of evolutionary adaptation, as if all creatures were evolutionary "perfect."

Humoring that, an adaptationist response would read as follows: Domestic pet warfare was emphatically not the problem cat and dog brains evolved to solve. They evolved in the wild: all dogs used to be wolves, and cats had every reason to fear them, and no reason to evolve a method of distinguishing good and bad dogs.

But even that involves some speculation.

Darwin was the first to highlight the difficulty of understanding why a specific trait did or did not evolve (Origin, ch. VII):

Why, in other quarters of the world, various animals belonging to this same order have not acquired either an elongated neck or a proboscis, cannot be distinctly answered; but it is as unreasonable to expect a distinct answer to such a question, as why some event in the history of mankind did not occur in one country, whilst it did in another.

The over-eager application of adaptationism -- making up evolutionary "just so" stories -- has been out of favor among evolutionary biologists since Stephen J. Gould famously criticized it in "The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme", Proc. of the Royal Society of London, Series B, Biological Sciences, 205, 1979.

Evolutionary psychology (which the question involves) has a bad reputation among biologists for being (in many cases) too adaptationist in its assumptions.

Evolution is not guaranteed to produce optimal or general solutions to problems -- i.e. a cat that knows what it should and should not trust. It cobbles together half-assed solutions to very specific problems -- a heuristic like "be afraid of anything snake-like," perhaps -- and it can only use existing material.

As a result, organisms easily get stuck in myriad sub-optimal solutions along the way. What might appear to us as an obvious way around a problem ("Don't waste resources fighting friendly animals") may not at all be obvious to mutation and natural selection! Ergo the famous caricature of evolution as a limited "tinker" rather than a brilliant "engineer" by François Jacob (Cf. "Evolution and Tinkering," Science, vol. 196, 1977)

EDIT: I should not that how often local optimums inhibit ideal adaptation is a very controversial topic in biology. Adaptationism has a strong following today, due in part to the success of evolutionary game theory at using adaptationist assumptions to model animal behavior.

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    Nice answer! Do cats and dogs even meet in the wild? Co-evolved tendencies in two species need an interaction of many generations before they emerge. And I can't imagine a tiger or puma or lion being instinctively afraid of a wolf, or dingo, or fox.
    – Ana
    Commented Mar 10, 2012 at 9:43
  • @Ana Canine and feline species meet in the wild. But while canines are usually pack animals most felines are loners. Single smaller felines would never stand a chance against a pack of canines, which may explain the flight behavior. en.wikipedia.org/wiki/Canidae#Social_behavior en.wikipedia.org/wiki/Felidae#Characteristics
    – Stefan
    Commented Oct 23, 2012 at 16:06
  • @Stefan - That makes sense, thanks for the explanation!
    – Ana
    Commented Oct 23, 2012 at 19:49
  • @Ana And with regards to Lions not being afraid of wolves. Read en.wikipedia.org/wiki/Spotted_hyena#Enemies_and_competitors . While Hyenas are closer related to felines their behavior is more like canines. Quote: In some cases, spotted hyenas are bold enough to feed alongside lions, and may occasionally force lions off a kill.
    – Stefan
    Commented Oct 23, 2012 at 20:45

Stanley Coren (in How to Speak Dog) notes that the body language of cats and dogs often mean opposite things (for example, a dog on his back is being submissive (or friendly) while a cat on its back is in a fighting posture) and speculates that this may be part of the historic problem between dogs and cats (he explains it better in this google book snippit)

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    I've come to the same conclusion myself, having had both dogs and cats most of my life. What a dog will do to say 'Hey let's play!' is what a cat interprets as 'I'm gonna cut you!'. Basic miscommunication, I'm sure, is a contributing factor.
    – morganpdx
    Commented Mar 25, 2014 at 0:24

One interesting take on this is the following research article: "The Escape Drive in Domestic Cats and the Dog and Cat Relationship" (Source: Behaviour, Volume 5, Number 1, 1953 , pp. 81-84(4))


Domestic cats reared without access to the street develop a pathological timidity, attributable to the escape drive being released by stimuli which would otherwise be subliminal. I suggest that in European and American cities dogs and cats form a commensality in which the cats provide the stimuli releasing the chasing instinct of dogs, and dogs the stimuli releasing the flight instinct of cats, thus mutually satisfying otherwise starved drives.

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    "thus mutually satisfying otherwise starved drives" seems to ascribe some weird notion of intent/agency to nature. Surely, in a world without dogs, cats wouldn't suffer from having their flight insticts "starved"; nor would it be starved, for that matter, provided that there'd still be vacuum cleaners. OH WELL, other than that I don't have an issue with the explanation. Commented May 11, 2011 at 21:18
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    Ir doesn't sound like that study has a control group of undomesticated cats and dogs (can't check though since it's pay-walled). Anecdotally in the few months I stayed in the Philippines the packs of dogs that was roaming around would chase the cats just as well as back in Europe (and all the cats were missing their tails).
    – Kit Sunde
    Commented May 12, 2011 at 8:15
  • So there should be several other pairs of animals with similar drives?
    – AIB
    Commented May 22, 2011 at 12:54
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    @AIB: Quite late to the game here, but I feel like you're definitely on the money there. As I see it, we know of this cat/dog trope because we've domesticated both as indoor animals. We don't keep pigs, roosters, sheep, deer, etc. indoors. Fighting and flight(ing) generally comes from fending off territory, fending off potential suitors, or finding food. It's possible that dogs just have to chase something, but it's probably a domesticated result of some older drive... ten to one that if we had other types of domesticated animals, we'd find similar behaviors.
    – erekalper
    Commented Jun 30, 2011 at 13:22
  • @ere - don't some aquarium fish behave aggressively? (never had fish but remember reading about it)
    – user5341
    Commented Jun 30, 2011 at 16:38

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