The “pit bull debate” is almost always played out as a polarized
conflict between the “pit bull lovers” on one side, who claim that a
dog’s behavior is all about the way it’s raised, and the “pit bull
haters” on the other side, who claim that a dog’s behavior is entirely
dictated by genetics.
Neither viewpoint is correct.
“To compare the relative importance of the two factors [nature and
nurture] separately is analogous to asking whether hydrogen or
oxygen is more important in the makeup of water.” —Steven R.
of Applied Dog Behavior and Training, Volume One.
A dog’s behavior occurs due to a combination of
both genetics and environment. This is also true of human beings, cats,
horses, rats, and any other living being on the planet. It is this
combination that makes each and every dog (or human, or any other living
thing) a unique individual.
**My purpose on this page is to assist the bewildered with some
easy-to-follow analogies and explanations.**
If you’re looking for serious scientific research, I highly recommend
the following books:
Genetics and the Social Behavior of the Dog by
John Paul Scott and John L. Fuller
Handbook of Applied Dog Behavior and Training (Volumes
1-3) by Steven R. Lindsay
Genetics and Temperament
All living things are born with a set of genetic blueprints. These genes
control physical appearance and general temperament.
Indeed, temperament is genetically (biologically) determined—but
temperament and behavior are not the same thing.
What exactly is temperament?
“Each individual—human or animal—is born with a definite tendency toward
varying degrees of emotional reactivity in the direction of behavioral
inhibition or excitability. . . . Clearly, genetic factors predispose
dogs to exhibit certain inevitable behavioral strengths or weaknesses.” (Stephen
R. Lindsay, Handbook of
Applied Dog Behavior and Training, Volume
The two things you should remember from this definition are:
1. Temperament is a
trait possessed by an individual, not
2. Temperament is a tendency or predisposition but
not a definitive action.
What this means can be boiled down rather simply: Temperament sets the
stage but does not write the play. Temperament is potential.
A dog’s genetics influence the possible behaviors which may be produced
by the dog, much the way a dial on an oven displays the possible
temperatures the oven could be set at.
Genetics limits potential behaviors. For
instance, I cannot teach a dog to sing opera, because genetics makes
this potential behavior impossible. In the same way, my kitchen oven’s
maximum temperature is 500 degrees, whether I like it or not.
Genetics allows potential behaviors. Dogs
may not be able to sing opera, but they have a wide range of barks,
yelps, and whines that they can use to communicate. Genetics makes these
noises possible and probable.
genetic component, defines the probability that
a particular behavior will be displayed in a particular circumstance.
each dog breed should have a certain temperament. To that end,
responsible breeders try to “breed for temperament.” But it’s not as
simple as it sounds! Unlike coat and eye colors, temperament isn’t
dictated by one, two, or even a handful of
genes. There’s no “shy” gene. There’s no “hyper” gene. Temperaments can
vary significantly even between litter mates.
In the end, the idea that breeds have specific temperaments is wishful
thinking. Even with a breed that is supposed to have a specific trait
(e.g., all Labs are fond of water), there are still many individual dogs
who do not meet the ideal temperament (e.g., some Labs do not like
water). Temperaments that are described in breed standards are ideals,
and the overwhelming majority of dogs fall short of the ideal.
“Biology and genetics define the limits of how and what an animal
learns, whereas experience dictates the moment-to-moment direction
of these behavioral changes.”—Steven R. Lindsay
Environment and Behavior
Temperament is not a guarantee of behavior. You could say that a person
is “quick-tempered,” but if they existed in a vacuum, would they still
be so? If nothing exists, what could cause a quick-tempered person to be
angry? Similarly, a dog may have a friendly temperament, but that dog is
friendly because it has people and dogs to act friendly towards; if it
was the only living creature on the planet, would it still be friendly?
For behavior to occur, environment must come into play. A
dog barks at the mailman, a person cries at a movie, and a horse gallops
away. These behaviors (barking, crying, galloping) are all prompted by
things that occur in the environment. If the mailman hadn’t walked by,
the dog would be silent. If the movie was a comedy, the person might
laugh instead of cry. The horse gallops because it has space to run. All
living creatures’ voluntary actions are prompted by the environment—the
surroundings and conditions in which they live.
A creature’s past environmental experiences may also influence current
behavior. This is the fundamental basis by which canine trainers and
behaviorists find their success. Because dogs, humans, and many other
living creatures learn and adapt to their environment, behavior may
change over time. A dog with a friendly temperament may still bite if it
is abused enough. With proper training and treatment, a dog with a
fearful temperament can learn not to cower at the sight of a broomstick.
The temperament doesn’t change, but behavior can.
Example. My dog
Felanie was born with a fearful temperament. She startled more easily
than other puppies. She tended to be more fearful of new situations. In
her early life, Fel’s fearful temperament was exacerbated by the abusive
environment she lived in. Herenvironment prompted
her to exhibit fear-based behaviors like slinking, darting, growling,
and warning barks.
Felanie’s temperament would never change, but her environment and her
behavior did change
when her abusive owner left and she joined our family. Felanie received
new, positive experiences in a loving household. She developed a new set
of behaviors that were friendly and social. Her fear-based behaviors
However, until the day she passed away, Fel remained a generally shy and
quiet dog. She would hang back, hesitate, and proceed more slowly, where
other dogs might race forward. Part of this was due to the early abuse,
but part of it was her temperament, her predisposition to be a bit more
cautious. I was always mindful that Felanie needed special attention
when something potentially scary was about to happen in her environment,
like a noisy party or a thunderstorm. By managing her environment, I was
able to control Felanie’s behavior as well.
All dogs have similar quirks related to their temperament, from the dog
with separation anxiety to the social butterfly who can’t resist running
across the street to play with the neighbor’s kids.
And all responsible dog owners adopt a variety of management techniques
to alter their dog’s behavior and cope with their dog’s temperament,
whether they realize it or not.
Aggression: Today’s battleground
“Used precisely, ‘aggression’ refers to fighting and means the act
of initiating an attack.”—John Paul Scott, Aggression
The “pit bull problem” seems to center around whether aggression is
inherent or learned. Aggression is
a behavior; a complex
behavior with many different possible causes, but a behavior
nevertheless. We know that behavior is influenced by environment and experience.
John Paul Scott was a renowned scientific researcher who was interested
in the interplay between genetics and behavior. He did experiments with
mice to determine whether highly aggressive mice could be created
through breeding. He came to this conclusion:
“The experiments with mice show us that aggression has to be
learned. Defensive fighting can be stimulated by the pain of an
attack, but aggression, in the strict sense of an unprovoked attack,
can only be produced by training. . . . Heredity can enter into the
picture only in such ways as lowering or raising the threshold of
stimulation, or modifying the physical equipment for fighting. . . .
In considering hereditary effects, we must always remember that the
environmental situation is also important.”—John Paul Scott, Aggression
In other words, according to Scott, aggression
is a learned behavior.
Further along these lines, some dogs have temperaments that are
conducive to aggressive behavior. That is, certain temperaments increase
the liklihood that a dog will exhibit aggression. A dog with a fearful
temperament, for example, may progress along the line from mere growling
to an outright bite more quickly than a less fearful dog in a similar
situation. Scott understands the influence of genetics in this regard;
this is why he writes that “heredity can enter into the picture only in
such ways as lowering or raising the threshold of stimulation.”
Temperament is the thing which raises or lowers that threshold and makes
a dog more or less likely to react aggressively in a given situation.
We have all heard stories about dogs who were not trained to be
aggressive, yet still attacked someone. Remember, however, that learning
occurs all the time, not just when a dog is formally trained by its
owner. Dogs learn life lessons from a variety of sources, including, but
not limited to, the owner. For example, a dog’s play, in which two dogs
pounce, growl, and tussle in a playful manner, is actually ritualized
aggression. When dogs play, they are learning and practicing a kind of
Here’s a typical scenario to illustrate how an “untrained” dog can
nevertheless learn to be aggressive.
Example. Fluffy has
a somewhat fearful temperament. He’s timid and submissive around other
dogs and people. Fluffy’s owner takes him back to the dog park several
times a week. Although she thinks Fluffy is getting socialization, in
truth Fluffy is totally overwhelmed by all the other dogs, and he spends
a lot of time trying to avoid them.
One day at the dog park, another young dog decides to challenge Fluffy.
Terrified, Fluffy defends himself. Fluffy’s owner lets the two dogs
“work it out.” Perhaps she chuckles because it’s so “cute” to watch the
two dogs “act so tough.” Perhaps she thinks that Fluffy will gain
confidence by “sticking up for himself.” Most likely, she simply isn’t
paying attention. Whatever the case, Fluffy’s owner doesn’t
intervene. Finally, Fluffy desperately asserts himself and manages to
get the other dog to back off. In Fluffy’s mind, defensive
aggression was successful because it brought about the desired result.
One day, a much bigger dog starts playing with Fluffy, but he’s too
rough and Fluffy starts getting scared. He doesn’t want to play anymore,
but the big dog won’t leave him alone. Fluffy decides to use defensive
aggression; he snarls, barks, and snaps at the big dog. The big dog is
surprised and runs off to find a nicer playmate. Once
again, Fluffy’s aggressive display was successful.
Now Fluffy knows how to get other dogs to go away. He just has to growl,
maybe snap his teeth, and they leave. It usually works. But one day a
puppy comes over to play with him, and the puppy doesn’t understand
Fluffy’s growl. The puppy keeps pouncing on him, biting his ears and
tail, and making him nervous. Fluffy gets more and more anxious. His
growls and snaps don’t seem to be working.
Finally, Fluffy decides to take it to the next level. He bites down on
the puppy’s face—hard. The puppy shrieks and struggles. People start
shouting, and Fluffy’s owner runs over. She is screaming and she starts
hitting Fluffy. Fluffy becomes even more terrified at the sudden
quantity of noise. He drops the puppy and cowers in fear. Fluffy’s owner
interprets his frightened cowering as a sign that “he
knew he did something wrong.” But
to Fluffy, the
hard bite worked. The
beastly little puppy went away, and in a few minutes Fluffy was safe and
sound in his owner’s car.
Fluffy’s owner doesn’t take him back to the dog park for several
weeks—much to his relief! After a while, though, Fluffy’s owner decides
that the bite incident was a fluke. She makes up excuses for Fluffy:
“the puppy provoked him” and “he knew he was bad, he won’t do it again.”
Unfortunately, fearful Fluffy has learned that an actual bite is much
more effective than mere growling. If he bites, the other dogs will
avoid him, and his owner will take him home! From the front seat of the
car, Fluffy sees the other dogs at the park and his heart beats faster.
He is nervous and anxious. He whines. His owner says, “Okay, okay, go
play” and she opens the door.
Fluffy runs straight to the nearest dog and launches a preemptive
mess with me! Chomp! Much
to Fluffy’s surprise, the strange dog doesn’t back down from this sudden
attack. It bites back, and now Fluffy is really scared.
His adrenaline starts flowing. Fluffy and the strange dog get into an
Fluffy’s owner and the strange dog’s owner both start shouting. Fluffy’s
owner pulls back on Fluffy’s collar. Fluffy misinterprets her screams.
To Fluffy, it seems like his owner is also scared of the other dog. Her
hand on his collar makes it seem like she’s supporting him. Fluffy’s
fears are confirmed, and he fights even more fiercely against his
terrifying canine opponent.
“But I didn’t teach him
to fight!” protests Fluffy’s owner as the vet stitches her dog up. And
But Fluffy has learned to
fight. Fluffy’s environment, including his learning experiences at the
dog park and his naive owner’s actions (or inaction), and his fearful
disposition worked together to foster his aggressive behavior. To make
matters worse, Fluffy’s owner hasn’t done anything to stop Fluffy
from learning and practicing aggression.
Until Fluffy’s owner learns to manage her dog’s fears and control her
dog’s environment, Fluffy will continue to attack other dogs.
Fluffy’s story demonstrates that aggressive
behavior does not require training or abuse. Aggressive
behavior is learned, but learning does not require formal training.
Aggressive behavior typically progresses along a line. It starts with
very minor signs, such as growling and raised fur. If the dog is given
more opportunities to rehearse aggression, the dog will learn, practice,
and improve, even without direct training.
Owners, especially those who rarely interact with their dogs, may not
even notice that the aggressive behavior is progressing until an animal
or a person gets seriously injured. Dog attack researcher Karen Delise
notes: “Many owners [of dogs that committed fatal attacks] expressed
shock at the ‘sudden’ and deadly aggressiveness of a pet they believed
they knew. But, in reality, most owners did not really know their dogs.
The fact that 25% of these dogs lived their lives at the end of a chain,
17% were running loose and 3% were kenneled indicates that many of these
dogs were not spending a lot of quality time with their owners.” (Fatal
Dog Attacks: The Stories Behind the Statistics)
The remedies for aggressive behavior are beyond the scope of this page;
I merely wish to clarify that aggression is not entirely dependent on
either genetics or environment.
Regardless of whether or not a dog is temperamentally inclined toward
undesirable behaviors like aggression, it
is the owner that
ultimately determines whether the dog actually has the opportunity to
react aggressively and rehearse aggressive behavior.
Owners who are responsible and involved do not give their dog the
opportunity to practice or escalate aggression! If an owner observes
that their dog growls or lunges at other dogs, a responsible owner might
employ a trainer or behavior counselor, who might recommend
desensitization, controlled socialization, confidence-building, or other
types of learning experiences. Or, the owner might decide to manage the
behavior by restricting their dog’s access to other dogs. Remember, it
takes two for aggression to occur: one to aggress and the other to
receive the aggression. A
dog cannot attack a victim that doesn’t exist.
By working to inhibit, reduce, or prevent aggressive behavior at the
first signs of a problem, the responsible owner breaks the cycle of
escalating aggression and significantly reduces the liklihood that their
dog will ever have the opportunity to behave aggressively.
Dog owners cannot change a dog’s genetics or temperament, but they can
strongly influence behavior by manipulating the dog’s environment and
owners are completely in control of the environment in which their dog
lives. They decide
where the dog spends its time and whether the dog interacts with other
people or animals. They expose (or fail to expose) the dog to social
situations and learning experiences. They teach (or fail to teach) the
dog how to behave. When a dog attacks, the blame rests squarely on the
owner’s shoulders for failing to manage the dog’s environment and
- Genetics (nature) sets a dog’s physical appearance and
temperament. Temperament influences the likelihood that a particular
behavior will occur in a particular situation.
- Each and every dog has an individual
- Environment (nurture) includes the conditions in which a dog lives
and the experiences the dog has.
- Behavior occurs only after the interaction of genetics and environment.
- Aggressive behavior requires environmental stimulation; there is no
internal drive to aggress.
- Dog owners cannot change genetics, but they have total control over
the dog’s environment and learning experiences. Dog owners therefore
have significant control over their dog’s behavior.
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