Male vs Female Dogs: Do Temperament Differences Matter

By Jessica Ennis, DVM, CVA

Breed care · August 16, 2026 · 6 min read

Sex tells you less about the dog in front of you than the breeder, the litter, and the first sixteen weeks do.

Before you decide sex is the deciding factor, check these first:

• Ask about the individual puppy or dog’s temperament test, not just its sex — breeders and shelters can usually describe boldness, resource guarding, and sociability from direct observation.
• Ask whether the dog will be spayed or neutered, and at what age — this changes hormone-driven behavior more than sex alone does.
• Ask about the line’s history with reactivity or resource guarding — genetics and rearing predict more than chromosomes do.
• Weigh household context — a second same-sex dog, small kids, or a multi-dog home changes which traits actually matter.
• Don’t let a breeder’s blanket claim (“females are calmer”) substitute for meeting the actual puppy.

The decision fork owners actually face

I get some version of this question in almost every puppy consult: “Should we get a male or a female?” Owners usually already have an answer in mind — a story about a friend’s sweet female Lab, or a warning about “dominant” males. My job isn’t to confirm the story. It’s to separate what sex reliably predicts from what it doesn’t, so the decision isn’t made on folklore.

Here’s the short version: sex predicts a handful of specific, hormone-linked behaviors reasonably well. It does not reliably predict overall friendliness, trainability, or how easy a dog is to live with. Litter, line, and rearing do more of that work than most owners expect.

What sex actually predicts

The clearest, most consistent sex difference shows up in intact dogs, not neutered or spayed ones. Male dogs that haven’t been neutered are more prone to roaming, mounting, urine marking, and male-to-male aggression — behaviors tied directly to circulating testosterone. An overview from Kinship on male versus female dog behavior notes that aggressiveness and boldness tend to score higher in males than females across several studies, while females show more inclination toward cooperative interactions with people.

That’s a real pattern, but it’s a narrower one than “males are more aggressive, period.” Unspayed females can be just as territorial, particularly toward other female dogs, and the size of any sex effect shrinks considerably once you account for individual variation within each sex. In my experience, the spread of temperament between two random male dogs is usually wider than the average difference between males and females as groups.

Spay and neuter status matters more than most owners realize

If you’re comparing “male dog behavior” to “female dog behavior,” you’re often actually comparing intact behavior to altered behavior, or vice versa, without realizing it. Spaying and neutering reliably reduce the hormone-driven behaviors — marking, roaming, mounting, some inter-male aggression — that people associate most strongly with sex differences in the first place.

But it isn’t a clean fix, and it isn’t free of tradeoffs. Research summarized by Sustainable Vet on behavioral changes after spay and neuter found a roughly 31% increase in fearfulness in dogs after sterilization, along with increases in touch sensitivity and excitability — effects that showed up in both sexes, not just one. Age at surgery, breed, and the individual dog’s baseline temperament all interact with the outcome. I tell owners plainly: don’t schedule the surgery expecting it to fix a behavior problem that isn’t hormone-driven. It won’t.

A case that changed how I frame this conversation

A family came into my clinic with two ten-week-old littermate puppies they were deciding between — a male and a female, both mixed retriever-type, both around twelve pounds. The father wanted the female because “males are too much work,” based on a dog he’d had twenty years earlier. During the fifteen-minute exam, the male puppy sat calmly through the whole thing and nosed my hand for attention. The female puppy squirmed, yelped at the thermometer, and bolted for the door the second it opened. Neither behavior was about sex. It was about two individual sixteen-week-old nervous systems reacting differently to a new room and a stranger in a white coat.

I told the family what I tell most people in that seat: pick the puppy whose temperament you just watched, not the sex you walked in expecting to prefer. They took the male. Eight months later, at his adolescent visit, he was still the calmer of the two on my exam table — and by then the family had stopped mentioning sex at all when they described him. What they talked about instead was his energy level, his food drive, and how he did around their toddler. That’s the conversation sex-based assumptions usually distract owners from having early enough.

Where behavior research actually gets measured

Some of the more rigorous behavioral data on dogs comes from standardized tools rather than anecdote. The C-BARQ: Canine Behavioral Assessment & Research Questionnaire: Canine Behavioral Assessment and Research Questionnaire, developed at the University of Pennsylvania, scores dogs across 14 behavioral categories — including stranger-directed aggression, dog-directed fear, trainability, and excitability — drawn from roughly 50,000 owner evaluations across more than 300 breeds. When researchers use tools like this to isolate sex as one variable among many, breed, age, and individual history routinely explain more of the variance in a dog’s score than sex does on its own. That’s worth remembering the next time someone tells you a whole sex is “the calm one” or “the stubborn one.”

What to actually screen for instead

If you’re choosing between two puppies or two adult dogs and sex is the tiebreaker you keep reaching for, redirect that energy toward things that predict temperament better:

• Line and littermate behavior. Ask the breeder or shelter what they’ve observed directly — resource guarding, startle recovery, sociability with strangers.
• Rearing and socialization window. The first several weeks with the breeder or foster shape confidence and reactivity more than sex does.
• Household fit. A high-energy working-line dog of either sex will be more work than a low-drive dog of either sex in a small apartment.
• Spay/neuter timing plan. Decide this with your vet before you decide on sex — it affects the hormone-driven behaviors people usually mean when they say “male” or “female” temperament.

If you’re weighing breed as heavily as sex, it’s worth reading up on breed-specific temperament patterns too — comparisons like Border Collie vs. Australian Shepherd or French Bulldog vs Boston Terrier get into how much energy level and structure vary within supposedly similar breeds, which is often the bigger lever than sex. If living space is part of the equation, Best Dog Breeds for Apartment Living walks through the routine-matching questions I ask owners before sex ever comes up.

Where I land

Sex isn’t meaningless — intact male behavior is a real, predictable category, and it’s fair to weigh it if you’re choosing between two intact dogs. But for the majority of pet owners, who will spay or neuter anyway, sex is one of the weaker predictors of the dog you’ll actually live with day to day. I’ve watched too many families anchor on “we want a female because females are gentler” and then bring home a female puppy who turns out bold, mouthy, and hard to settle — while the “too much” male littermate would have suited their calm household better.

My honest recommendation: meet the individual dog, ask direct questions about what the breeder or shelter has observed, and plan your spay/neuter timing with your vet. Let sex be a minor factor in the decision, not the deciding one.