Male vs Female Dogs: Do Temperament Differences Matter?

By Jessica Ennis, DVM, CVA

Breed care · August 5, 2026 · 6 min read

Sex nudges the odds on a few specific behaviors, but it will never tell you what the dog in front of you is actually like.

Quick answer first, because clients ask me this before anything else at a puppy visit:

• Sex explains a small slice of temperament variance — breed, individual genetics, and early socialization explain far more.
• Intact males are more prone to roaming, marking, and mounting; the drivers are largely hormonal, not “maleness” as a personality.
• Females may show more resource-guarding and same-sex aggression toward other females in some studies, though findings are mixed.
• Spaying or neutering shifts some of these behaviors, but timing and individual response vary, and it is not a temperament fix.
• If you’re choosing a puppy, weight breed line, parents’ temperament, and your own household over the coin flip of sex.

I want to walk through why that checklist holds up, because most of what people believe about “boy dogs” and “girl dogs” is folklore dressed up as fact.

A question I get in almost every puppy consult

A family came in a few months ago with two kids, a fenced quarter-acre yard, and a strong opinion: they wanted a female because “males are too much” and someone at the dog park had told them so with real conviction. I asked what breed they were considering. Golden Retriever, eight weeks old, from a breeder with health-tested parents. I told them what I tell most families in that chair — the sex of that specific puppy would matter less to their daily life than which particular puppy in that litter they picked, and less than the breed itself. They took the male. He’s a easygoing, food-motivated dog who sleeps through thunderstorms. His sister, who went to a different family, apparently guards the couch. Neither outcome was predicted by chromosomes.

What the research on sex differences actually says

The honest starting point is that sex-linked behavior differences in dogs are real but small, and they cluster around a handful of specific behaviors rather than “personality” broadly. A review in Behavioral and Perceptual Differences between Sexes in Dogs: An Overview: Journal of Veterinary Behavior summarizing behavioral and perceptual differences between sexes found that males more often show roaming, mounting, and marking — behaviors tied closely to testosterone — while females showed somewhat different patterns around social and maternal behaviors. The differences were consistent enough to measure, but they were not large enough to use as a reliable predictor for an individual dog.

A separate study on undesirable behaviors across The Influence of Breed, Sex, Origin and Housing Conditions on Undesirable Behaviors in Ancient Dog Breeds: ancient dog breeds found that breed, sex, origin, and housing conditions all contributed to behavior outcomes — and notably, aggressive behaviors were more prevalent in females than males in that particular sample, which runs against the popular assumption that males are the more aggressive sex. That inconsistency across studies is itself the finding: sex effects on aggression are not one-directional, and they depend heavily on context, breed, and what “aggression” was actually measured against (strangers, other dogs, resource guarding, the owner).

Where hormones do the talking

Most of what people label a “male trait” is really a hormone effect, which is why neuter status changes the picture more than sex alone does. The American Veterinary Medical Association: AVMA’s gonadectomy resources note that decisions about spaying and neutering require individualized professional judgment, because the behavioral and health effects vary by breed, age at surgery, and the individual dog — there is no universal timeline that works for every patient. In practice, I see roaming and marking drop off in a lot of neutered males, and heat-cycle restlessness disappear in spayed females. But calling a dog “calmer” after surgery is different from saying sex predicted the starting temperament. It didn’t; the hormones did, and removing them changes the hormones, not the dog’s underlying disposition toward people, novelty, or other dogs.

The scene that changed how I counsel this

I had a client a couple of years back with two Border Collies from the same working line, a brother and sister, both intact, both around eighteen months old when I met them. She was convinced the male would be the “harder” one to manage because he was, in her words, “all boy.” Within a year it was the female who needed a referral to a veterinary behaviorist for noise reactivity and resource guarding around food, something that had started gradually after a move to a new house with a busier street. The male was, by comparison, unbothered by nearly everything — new people, new dogs, thunderstorms. I don’t tell that story to argue females are harder; I tell it because it’s the exact reverse of what she expected walking in, and that gap between expectation and reality is where most bad breed-and-sex decisions get made. What predicted the difference wasn’t sex. It was the individual dog’s genetics, plus a stressful environmental change that hit one of them harder.

What I actually tell people to prioritize instead

If you’re picking between two puppies, or deciding whether sex should factor into your decision at all, here’s the order I use with clients:

1. Breed and line first. A French Bulldog vs Boston Terrier comparison, for instance, turns far more on airway conformation and breed-typical energy than on which one is male. Breed and working lineage predict far more variance in temperament than sex does.

2. The individual puppy’s behavior, not the litter average. Watch how a specific puppy responds to new sounds, handling, and other dogs before you decide anything based on sex.

3. Your household’s actual constraints. If you have another intact dog of the same sex at home, same-sex pairs can be more prone to conflict in some households — that’s a real, practical reason sex might matter for you, separate from temperament stereotypes.

4. Spay/neuter timing, discussed with your vet. This affects behavior more directly than sex alone, and the right timing depends on breed, size, and health history.

If you’re weighing multiple factors at once — living space, activity level, whether this is your first dog — it’s worth reading a broader breed guide before sex even enters the conversation; our guides on best dog breeds for first-time owners and best dog breeds for apartment living both walk through the questions that actually predict a good match.

The counterargument, and why I still land where I do

The strongest pushback I hear is anecdotal but not unreasonable: “every male dog I’ve ever owned has marked in the house, and every female hasn’t.” That’s a real pattern, and it’s not wrong — it maps onto the hormonal roaming/marking findings above. But it’s a narrow behavior, not a temperament. Marking says something about testosterone and territory, not about whether a dog will be affectionate, trainable, anxious, or good with kids. I’d rather a client pick the puppy with the calm eye contact and the willingness to be handled than the “right” sex on paper, because the traits that make daily life easier or harder — reactivity, independence, food drive, recovery from startle — don’t sort cleanly by sex in the research or in my exam room.

The short version

Sex differences in dog temperament are real at the population level for a short list of hormone-driven behaviors — roaming, marking, mounting, and some aggression patterns — and the effect sizes are modest. They are not a reliable way to predict what an individual dog will be like to live with. Breed, individual genetics, early experience, and your household situation carry far more weight. If you want a decisive rule from me: choose the specific dog in front of you, not the sex on the intake form.