1. Headline
  1. Headline
By
updated 4/27/2011 3:52:16 PM ET 2011-04-27T19:52:16

Male dogs are from Mars, female dogs are from … Pluto?

  1. Stories from
    1. Cameron Diaz's Boyfriend Benji Madden: 'I'm Really Happy Right Now'
    2. Kim Kardashian Appears to Be Having a No-Makeup Moment: PHOTOS
    3. Police Arrest Florida Mom for Letting 7-Year-Old Son Walk to Park Alone
    4. Once Upon a Time's Lana Parrilla Gets Married in Real-Life Fairy Tale
    5. Abigail Hernandez, Missing for 9 Months, Says She's 'Better Every Day'

True, dogs aren't exactly a fertile market for self-help manuals. But a new study finds that the brains of male and female canines are not the same — and in at least one task, the females have an edge.

The researchers aren't sure of the root cause of these doggie brain differences, but the study points to the need to take sex into account when trying to understand how animals think.

"When you start looking, you get some very interesting and instructive results," study researcher Corsin Müller, a cognitive biologist at the University of Vienna, told LiveScience.

Peering into the canine mind
Müller and his colleagues tested female and male dogs — "completely normal family dogs," Muller said — to see whether they understand a concept called "object permanence," which is the realization that objects don't disappear and don't change form just because they go out of sight. Children learn this physical law around the age of 1 or so. The question, Müller said, was whether dogs understand it too. [Read: 10 Things You Didn't Know About the Brain ]

The researchers set up a wooden board and a system of blue tennis balls attached to strings. The dogs, 25 female and 25 male, watched one of four scenarios: A small ball disappearing behind the board and re-emerging; a large ball disappearing and re-emerging; a large ball disappearing and a small ball emerging; or a small ball disappearing and a large ball emerging. The first two experiments were the "expected" conditions, which didn't break any laws of nature. The second two events, in which a ball would seem to shrink or grow while out of sight, were the "unexpected" or impossible conditions.

The researchers measured the dogs' ability to understand that something impossible had just happened by measuring how long they stared at the emerging ball. The experiments are similar to those used to understand infant cognition.

"If something unexpected or, say, impossible is to happen, children and animals will look longer at the event," Müller said.

Who's smarter?
At first glance, dogs did seem to look longer at the event when the ball seemed to mysteriously shrink or grow. But when the researchers broke the results down by dogs' sex, they found that male dogs hadn't noticed anything odd at all. Female dogs, on the other hand, stared at the "unexpected" conditions for more than 30 seconds on average, more than three times longer than the 10 seconds or so they spent looking at the balls when they didn't change size.

The sex difference emerged across breeds, which ranged from large to small, purebred to mixed, Müller said.

There are three possible explanations for why male and female dogs — or any animal — might show sex-based brain differences. The first is that evolutionary pressures in the past might have subtly shifted male and female brains. If one sex hunts while the other builds nests, for example, the nest-builder might gradually become better at spatial reasoning, while the hunter might evolve to be better at navigating through unfamiliar territory. Another possibility is that brain differences arise because of childbearing duties; a female solely responsible for rearing her offspring might show greater nurturing skills than a male that has little to do with his offspring after mating.

Neither of these is a good explanation for dogs because their sex-specific differences seem very limited, Müller wrote. Instead, he suspects a third possibility: That the sex differences in the brain are a side effect of other biological sex differences.

"[Most likely,] this is just a byproduct of sex hormones working on the brain, without necessarily having a function," Müller said.

Although this experiment gave female dogs the cognitive edge, Müller said it's likely that future findings of sex differences would even the intelligence scale.

In humans, Müller said, "there's tons of differences you can find, but for everything where you find men are better than women, you can find something where women are better than men."

© 2012 LiveScience.com. All rights reserved.

Discuss:

Discussion comments

,

Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments

More on TODAY.com

  1. ‘She was all over me!' Regis dishes on co-hosting with Kathie Lee

    TrydayFriday was a laugh-out-loud, fun-filled show as KLG invited her old pal to co-host.

    8/1/2014 2:01:46 PM +00:00 2014-08-01T14:01:46
  2. 6 GIFs show why this animal segment is the best one ever

    When animals visit Kathie Lee and Hoda, things always get interesting. But when Regis is co-hosting, it gets down right outrageous!"Does Hoda have a pith helmet here I can put on?

    8/1/2014 2:40:51 PM +00:00 2014-08-01T14:40:51
  3. TODAY the musical! KLG puts together show featuring anchors

    The special Friday edition of TODAY's Fourth Hour was full of surprises — not only did Regis Philbin fill in for Hoda, but Kathie Lee made a big announcement: Get ready for TODAY the musical! "It's going to be live and it's going to be so much fun," an excited Kathie Lee said.

    8/1/2014 2:14:15 PM +00:00 2014-08-01T14:14:15
  4. TODAY
  1. US scrambles to retrieve Ebola-infected Americans

    Health officials are trying to get at least one American patient infected with Ebola virus back from West Africa for treatment. Emory University Hospital said it was ready to take care of one patient at a special isolation unit.

    8/1/2014 3:47:06 PM +00:00 2014-08-01T15:47:06