Once a week.
Subscribe to our weekly newsletter.
6 reasons dogs truly are man’s best friend
Research suggests dog ownership may improve heart health, decrease depression, and even help you live longer.
- Dogs have been man's best friend for at least the past 15,000 years.
- Science now shows that this symbiotic relationship has been as beneficial for humans as their canine companions.
- Benefits of dog ownership include familial ties, a reduce risk of schizophrenia, and improved cardiovascular health.
Under cover of darkness, a pack of ancient wolves slowly stalk the camps of our nomadic ancestors. But they are not on the prowl. These timid, congenial Canidaes have discovered they can scavenge human kills and midden piles for more reward, and far less risk, than the hunt.
Over successive generations, their offspring grow more docile and more dependent on their human benefactors. In time humans adopt these four-legged moochers, taking them into their service with the tacit agreement of better food and companionship. And so, the human-dog relationship was born.
That's one possibility at least. All that's generally agreed upon is that dogs became man's best friend as early as 15,000 years ago — though some fossil evidence suggests domestication as far back as 30,000 years. As science writer James Gorman points out, this means we loved our tail-wagging besties before inventing agriculture, language, or permanent homes and even before we domesticated cows, goats, and, of course, cats.
"As we became friends with them, they became friends with us, and we have a dependency that's charming," Bill Nye, science guy and lover of all good dogs, told us in a 2015 interview. "It's enriched both the dog lives and the human lives."
For humans, the perks of the dog-human relationship run much deeper than games of fetch or a handy excuse to go for a nice, long walk.
Dogs see us as family
Dogs see their people as family, and the feeling seems to be mutual.
It's not our imaginations or a poetic attempt to explain behavior through personification. Dogs do view their people as family.
Cognition scientists at Emory University placed dogs in an MRI machine and scanned their brains while presenting them with different odors. Some aromas were of food. Others were from other dogs. And some were from the dogs' human companions. The dogs' brains' reward centers lit up most when presented with the human scents, showing they prioritized human relationships.
These results bolstered other research that shows dogs act similarly to human sounds and that they are the only non-primates to run toward humans for protection and comfort.
Dogs reduce the risk of schizophrenia
A little girl meets Lothair and Molly, two certified therapy dogs, at U.S. Air Force Base Hospital Langley.
Dogs may be able to curb the risk of some mental diseases. That's the conclusion of research published in the peer-reviewed journal PLoS ONE, which found a link between dog ownership and a reduced risk of schizophrenia.
The researchers looked at 1,371 men and women across the socioeconomic spectrum. Roughly 400 participants suffered from schizophrenia, another 400 from bipolar disorder, and about 600 were controls. After a survey in which the participants were asked about pets, the researchers compared ownership with rates of mental illness.
They discovered that dog ownership before the age of 13 correlated with a 25 percent reduced risk of schizophrenia. Participants who owned dogs in the first years of life showed the largest protective effect.
"There are several plausible explanations for this possible 'protective' effect from contact with dogs," lead author Robert Yolken said in a statement. "Perhaps something in the canine microbiome that gets passed to humans and bolsters the immune system against or subdues a genetic predisposition to schizophrenia."
Sorry, ailurophiles. Cats did not show a similar link between ownership and a reduced risk of mental diseases.
Dogs are your heart's best friend, too
Regular walks with your dog is great exercise and boosts cardiovascular health.
The health benefits aren't just in the mind. Preliminary research published in Mayo Clinic Proceedings: Innovations, Quality & Outcomes suggests that pet ownership boosts heart health, especially if that pet is a dog.
Researchers evaluated roughly 1,800 participants using the American Heart Association's Life's Simple 7, seven life factors that people can improve to help achieve cardiovascular well-being. They then compared the health of pet owners with those who did not own pets and found a correlation between dog ownership and heart health. The researchers associated this salubrious effect with increased engagement and physical activity.
"In general, people who owned any pet were more likely to report more physical activity, better diet and blood sugar at an ideal level," Andrea Maugeri, a researcher with the International Clinical Research Center at St. Anne's University Hospital in Brno, said in a statement. "The greatest benefits from having a pet were for those who owned a dog, independent of their age, sex and education level."
Follow-up evaluations are scheduled until 2030.
Dogs make life better (and longer)
An older gentleman sits with his canine companion.
Better heart health means a better chance to live longer. That's according to a recent study and meta-analysis published in Circulation: Cardiovascular Quality and Outcomes.
The research found that dog owners who survived a heart attack were at a 33 percent reduced risk of early death compared to non-dog survivors. The same held true for stroke survivors (27 percent). Better still, dog ownership correlated with a 24 percent reduced risk of all-cause mortality, likely explained by an increase in physical activity and a decrease in depression and loneliness.
A study published in Scientific Reports corroborates a canine's life-giving, heart-healthy impact. The researchers reviewed the national registries for more than 3.4 million Swedes with no cardiovascular disease before 2001. Looking at the association between dog ownership and cardiovascular health, they found that single dog owners had a lowered risk of death, either due to cardiovascular disease (11 percent) or other causes (33 percent).
In a statement, lead junior author Mwenya Mubanga noted, "A very interesting finding in our study was that dog ownership was especially prominent as a protective factor in persons living alone, which is a group reported previously to be at higher risk of cardiovascular disease and death than those living in a multi-person household. Perhaps a dog may stand in as an important family member in the single households."
Dogs teach us ways to learn
Put simply, dogs are better at ignoring bad advice than their human peers. Research out of Yale University's Canine Cognition Center tasked dogs with retrieving treats from a puzzle. The researchers presented the steps to solve the puzzle but included many extraneous steps in the demonstration. When it was the dogs' turn, they nimbly skipped the unnecessary steps, thereby showing their ability to filter information effectively.
How did human children perform? Not so great. The children settled on pure imitation, regardless of whether a step proved useful in solving the puzzle.
"This tells us something really important about how humans learn relative to other animals," Big Think author Arpan Bhattacharyya wrote on the study. "We're really trusting of the information that we get from other individuals – even more trusting than dogs are.
"And what this means is we have to be really careful about the kinds of information we present ourselves with. We're not going to have the right filter for bad information, so we should stick to looking at information that's going to be positive, information that's going to be good."
Dogs teach us about ourselves
Dogs really do resemble their owners.
Dogs resemble their owners in more ways than floppy jowls or a perky gait. Dogs mirror their owners' personalities, and owners can use this information to better understand themselves.
Research published in the Journal of Research in Personality surveyed more than 1,600 dog owners, representing about 50 different breeds. They found that dog owners shaped their dogs' personalities. Extroverted owners rated their dogs as more active and playful, while the owners of more fearful dogs tended to exhibit more negative emotions. Similarly, more agreeable owners were guardians of less aggressive pets.
"We expected the dogs' personalities to be fairly stable because they don't have wild lifestyle changes humans do, but they actually change a lot. We uncovered similarities to their owners, the optimal time for training and even a time in their lives that they can get more aggressive toward other animals," lead author William Chopik said in a release.
Another study in Scientific Reports showed similar findings regarding stress. The researchers took hair and fur samples from owners and their dogs to measure both for the stress hormone cortisol. They found a correlation in long-term stress between the two.
More than simply good dogs
These are six ways that science has discovered dogs aid their interspecies partner. As genetic research advances, dogs may prove they are man's best friends in unforeseen ways. Scientists studying the canine genome have found a number of canine disorders that closely resemble those found in humans, including some cancers. Further study may provide a wealth of information that could help us solve our own genetic mysteries.
- Dog Owners Experience Reduced Risk for Cardiovascular Problems ... ›
- Dogs in the Workplace Mean Better Mental Health - Big Think ›
- Is Dog Man's Best Friend Because of Oxytocin? ›
Is information the fifth form of matter?
- Researchers have been trying for over 60 years to detect dark matter.
- There are many theories about it, but none are supported by evidence.
- The mass-energy-information equivalence principle combines several theories to offer an alternative to dark matter.
The “discovery” of dark matter
We can tell how much matter is in the universe by the motions of the stars. In the1920s, physicists attempting to do so discovered a discrepancy and concluded that there must be more matter in the universe than is detectable. How can this be?
In 1933, Swiss astronomer Fritz Zwicky, while observing the motion of galaxies in the Coma Cluster, began wondering what kept them together. There wasn't enough mass to keep the galaxies from flying apart. Zwicky proposed that some kind of dark matter provided cohesion. But since he had no evidence, his theory was quickly dismissed.
Then, in 1968, astronomer Vera Rubin made a similar discovery. She was studying the Andromeda Galaxy at Kitt Peak Observatory in the mountains of southern Arizona when she came across something that puzzled her. Rubin was examining Andromeda's rotation curve, or the speed at which the stars around the center rotate, and realized that the stars on the outer edges moved at the exact same rate as those at the interior, violating Newton's laws of motion. This meant there was more matter in the galaxy than was detectable. Her punch card readouts are today considered the first evidence of the existence of dark matter.
Many other galaxies were studied throughout the '70s. In each case, the same phenomenon was observed. Today, dark matter is thought to comprise up to 27% of the universe. "Normal" or baryonic matter makes up just 5%. That's the stuff we can detect. Dark energy, which we can't detect either, makes up 68%.
Dark energy is what accounts for the Hubble Constant, or the rate at which the universe is expanding. Dark matter on the other hand, affects how "normal" matter clumps together. It stabilizes galaxy clusters. It also affects the shape of galaxies, their rotation curves, and how stars move within them. Dark matter even affects how galaxies influence one another.
Leading theories on dark matter
NASA writes: 'This graphic represents a slice of the spider-web-like structure of the universe, called the "cosmic web." These great filaments are made largely of dark matter located in the space between galaxies.'
Credit: NASA, ESA, and E. Hallman (University of Colorado, Boulder)
Since the '70s, astronomers and physicists have been unable to identify any evidence of dark matter. One theory is it's all tied up in space-bound objects called MACHOs (Massive Compact Halo Objects). These include black holes, supermassive black holes, brown dwarfs, and neutron stars.
Another theory is that dark matter is made up of a type of non-baryonic matter, called WIMPS (Weakly Interacting Massive Particles). Baryonic matter is the kind made up of baryons, such as protons and neutrons and everything composed of them, which is anything with an atomic nucleus. Electrons, neutrinos, muons, and tau particles aren't baryons, however, but a class of particles called leptons. Even though the (hypothetical) WIMPS would have ten to a hundred times the mass of a proton, their interactions with normal matter would be weak, making them hard to detect.
Then there are those aforementioned neutrinos. Did you know that giant streams of them pass from the Sun through the Earth each day, without us ever noticing? They're the focus of another theory that says that neutral neutrinos, that only interact with normal matter through gravity, are what dark matter is comprised of. Other candidates include two theoretical particles, the neutral axion and the uncharged photino.
Now, one theoretical physicist posits an even more radical notion. What if dark matter didn't exist at all? Dr. Melvin Vopson of the University of Portsmouth, in the UK, has a hypothesis he calls the mass-energy-information equivalence. It states that information is the fundamental building block of the universe, and it has mass. This accounts for the missing mass within galaxies, thus eliminating the hypothesis of dark matter entirely.
To be clear, the idea that information is an essential building block of the universe isn't new. Classical Information Theory was first posited by Claude Elwood Shannon, the "father of the digital age" in the mid-20th century. The mathematician and engineer, well-known in scientific circles—but not so much outside of them, had a stroke of genius back in 1940. He realized that Boolean algebra coincided perfectly with telephone switching circuits. Soon, he proved that mathematics could be employed to design electrical systems.
Shannon was hired at Bell Labs to figure out how to transfer information over a system of wires. He wrote the bible on using mathematics to set up communication systems, thereby laying the foundation for the digital age. Shannon was also the first to define one unit of information as a bit.
There was perhaps no greater proponent of information theory than another unsung paragon of science, John Archibald Wheeler. Wheeler was part of the Manhattan Project, worked out the "S-Matrix" with Niels Bohr and helped Einstein develop a unified theory of physics. In his later years, he proclaimed, "Everything is information." Then he went about exploring connections between quantum mechanics and information theory.
He also coined the phrase "it from bit" or that every particle in the universe emanates from the information locked inside it. At the Santa Fe Institute in 1989, Wheeler announced that everything, from particles to forces to the fabric of spacetime itself "… derives its function, its meaning, its very existence entirely … from the apparatus-elicited answers to yes-or-no questions, binary choices, bits."
Part Einstein, part Landauer
Vopson takes this notion one step further. He says that not only is information the essential unit of the universe but also that it is energy and has mass. To support this claim, he unifies and coordinates special relativity with the Landauer Principle. The latter is named after Rolf Landauer. In 1961, he predicted that erasing even one bit of information would release a tiny amount of heat, a figure which he calculated. Landauer said this proves information is more than just a mathematical quantity. This connects information to energy. Through experimental testing over the years, the Landauer Principle has held up.
Vopson says, "He [Landauer] first identified the link between thermodynamics and information by postulating that logical irreversibility of a computational process implies physical irreversibility." This indicates that information is physical, Vopson says, and demonstrates the link between information theory and thermodynamics.
In Vopson's theory, information, once created has "finite and quantifiable mass." It so far applies only to digital systems, but could very well apply to analogue and biological ones too, and even quantum or relativistic-moving systems. "Relativity and quantum mechanics are possible future directions of the mass-energy-information equivalence principle," he says.
In the paper published in the journal AIP Advances, Vopson outlines the mathematical basis for his hypothesis. "I am the first to propose the mechanism and the physics by which information acquires mass," he said, "as well as to formulate this powerful principle and to propose a possible experiment to test it."
The fifth state of matter
To measure the mass of digital information, you start with an empty data storage device. Next, you measure its total mass with a highly sensitive measuring apparatus. Then, you fill it and determine its mass. Next, you erase one file and evaluate it again. The trouble is, the "ultra-accurate mass measurement" device the paper describes doesn't exist yet. This would be an interferometer, something similar to LIGO. Or perhaps an ultrasensitive weighing machine akin to a Kibble balance.
"Currently, I am in the process of applying for a small grant, with the main objective of designing such an experiment, followed by calculations to check if detection of these small mass changes is even possible," Vopson says. "Assuming the grant is successful and the estimates are positive, then a larger international consortium could be formed to undertake the construction of the instrument." He added, "This is not a workbench laboratory experiment, and it would most likely be a large and costly facility." If eventually proved correct, Vopson will have discovered the fifth form of matter.
So, what's the connection to dark matter? Vopson says, "M.P. Gough published an article in 2008 in which he worked out … the number of bits of information that the visible universe would contain to make up all the missing dark matter. It appears that my estimates of information bit content of the universe are very close to his estimates."
The experience of life flashing before one's eyes has been reported for well over a century, but where's the science behind it?
At the age of 16, when Tony Kofi was an apprentice builder living in Nottingham, he fell from the third story of a building. Time seemed to slow down massively, and he saw a complex series of images flash before his eyes.
As he described it, “In my mind's eye I saw many, many things: children that I hadn't even had yet, friends that I had never seen but are now my friends. The thing that really stuck in my mind was playing an instrument". Then Tony landed on his head and lost consciousness.
When he came to at the hospital, he felt like a different person and didn't want to return to his previous life. Over the following weeks, the images kept flashing back into his mind. He felt that he was “being shown something" and that the images represented his future.
Later, Tony saw a picture of a saxophone and recognized it as the instrument he'd seen himself playing. He used his compensation money from the accident to buy one. Now, Tony Kofi is one of the UK's most successful jazz musicians, having won the BBC Jazz awards twice, in 2005 and 2008.
Though Tony's belief that he saw into his future is uncommon, it's by no means uncommon for people to report witnessing multiple scenes from their past during split-second emergency situations. After all, this is where the phrase “my life flashed before my eyes" comes from.
But what explains this phenomenon? Psychologists have proposed a number of explanations, but I'd argue the key to understanding Tony's experience lies in a different interpretation of time itself.
When life flashes before our eyes
The experience of life flashing before one's eyes has been reported for well over a century. In 1892, a Swiss geologist named Albert Heim fell from a precipice while mountain climbing. In his account of the fall, he wrote is was “as if on a distant stage, my whole past life [was] playing itself out in numerous scenes".
More recently, in July 2005, a young woman called Gill Hicks was sitting near one of the bombs that exploded on the London Underground. In the minutes after the accident, she hovered on the brink of death where, as she describes it: “my life was flashing before my eyes, flickering through every scene, every happy and sad moment, everything I have ever done, said, experienced".
In some cases, people don't see a review of their whole lives, but a series of past experiences and events that have special significance to them.
Explaining life reviews
Perhaps surprisingly, given how common it is, the “life review experience" has been studied very little. A handful of theories have been put forward, but they're understandably tentative and rather vague.
For example, a group of Israeli researchers suggested in 2017 that our life events may exist as a continuum in our minds, and may come to the forefront in extreme conditions of psychological and physiological stress.
Another theory is that, when we're close to death, our memories suddenly “unload" themselves, like the contents of a skip being dumped. This could be related to “cortical disinhibition" – a breaking down of the normal regulatory processes of the brain – in highly stressful or dangerous situations, causing a “cascade" of mental impressions.
But the life review is usually reported as a serene and ordered experience, completely unlike the kind of chaotic cascade of experiences associated with cortical disinhibition. And none of these theories explain how it's possible for such a vast amount of information – in many cases, all the events of a person's life – to manifest themselves in a period of a few seconds, and often far less.
Thinking in 'spatial' time
An alternative explanation is to think of time in a “spatial" sense. Our commonsense view of time is as an arrow that moves from the past through the present towards the future, in which we only have direct access to the present. But modern physics has cast doubt on this simple linear view of time.
Indeed, since Einstein's theory of relativity, some physicists have adopted a “spatial" view of time. They argue we live in a static “block universe" in which time is spread out in a kind of panorama where the past, the present and the future co-exist simultaneously.
The modern physicist Carlo Rovelli – author of the best-selling The Order of Time – also holds the view that linear time doesn't exist as a universal fact. This idea reflects the view of the philosopher Immanuel Kant, who argued that time is not an objectively real phenomenon, but a construct of the human mind.
This could explain why some people are able to review the events of their whole lives in an instant. A good deal of previous research – including my own – has suggested that our normal perception of time is simply a product of our normal state of consciousness.
In many altered states of consciousness, time slows down so dramatically that seconds seem to stretch out into minutes. This is a common feature of emergency situations, as well as states of deep meditation, experiences on psychedelic drugs and when athletes are “in the zone".
The limits of understanding
But what about Tony Kofi's apparent visions of his future? Did he really glimpse scenes from his future life? Did he see himself playing the saxophone because somehow his future as a musician was already established?
There are obviously some mundane interpretations of Tony's experience. Perhaps, for instance, he became a saxophone player simply because he saw himself playing it in his vision. But I don't think it's impossible that Tony did glimpse future events.
If time really does exist in a spatial sense – and if it's true that time is a construct of the human mind – then perhaps in some way future events may already be present, just as past events are still present.
Admittedly, this is very difficult to make sense of. But why should everything make sense to us? As I have suggested in a recent book, there must be some aspects of reality that are beyond our comprehension. After all, we're just animals, with a limited awareness of reality. And perhaps more than any other phenomenon, this is especially true of time.
Might as well face it, you're addicted to love.
- Many writers have commented on the addictive qualities of love. Science agrees.
- The reward system of the brain reacts similarly to both love and drugs
- Someday, it might be possible to treat "love addiction."
Since people started writing, they've written about love. The oldest love poem known dates back to the 21st century BCE. For most of that time, writers also apparently have been of two (or more) minds about it, announcing that love can be painful, impossible to quit, or even addictive — while also mentioning how nice it is.
The idea of love as an addiction is one that is both familiar and unsettling. Surely it can't be the case that our mutual love with our partner — a thing that can produce euphoria, consumes a great deal of our time, and which we fear losing — can be compared to a drug habit? But indeed, many scientists have turned their attention to the idea of "love addiction" and how your brain on drugs might resemble your brain in love.
Love and other drugs
In a 2017 article published in the journal Philosophy, Psychiatry, & Psychology, a team of neuroethicists considered the idea that love is addicting and held the idea up to science for scrutiny.
They point out that the leading model of addiction rests on the notion of a drug causing the brain to release an unnatural level of reward chemicals, such as dopamine, effectively hijacking the brain's reward system. This phenomenon isn't strictly limited to drugs, though they are more effective at this process than other things. Rats can get a similar rush from sugar as from cocaine, and they can have terrible withdrawal symptoms when the sugar crash kicks in.
On the structural level, there is a fair amount of overlap between the parts of the brain that handle love and pair-bonding and the parts that deal with addiction and reward processing. When inside an MRI machine and asked to think about the person they love romantically, the reward centers of people's brains light up like Broadway.
Love as an addiction
These facts lead the authors to consider two ideas, dubbed the "narrow" and "broad" views of love as an addiction.
The narrow view holds that addiction is the result of abnormal brain processes that simply don't exist in non-addicts. Under this paradigm, "food-seeking or love-seeking behaviors are not truly the result of addiction, no matter how addiction-like they may outwardly appear." It could be that abnormal processes cause the brain's reward system to misfire when exposed to love and to react to it excessively.
If this model is accurate, love addiction would be a rare thing — one study puts it around five to ten percent of the population — but could be considered a disorder similar to others and caused by faulty wiring in the brain. As with other addictions, this malfunction of the reward system could lead to an inability to fully live a typical life, difficulty having healthy relationships, and a number of other negative consequences.
The broad view looks at addiction differently, perhaps even radically.
It begins with the idea that addiction exists on a spectrum of motivations. All of our appetites, including those for food and water, exist on this spectrum and activate similar parts of the brain when satisfied. We can have appetites for anything that taps into our reward system, including food, gambling, sex, drugs, and love. For most people most of the time, our appetites are fairly temperate, if recurring. I might be slightly "addicted" to food — I do need some a few times per day — but that "addiction" doesn't have any negative effects on my health.
An appetite for cocaine, however, is rarely temperate and usually dangerous. Likewise, a person's appetite for love could reach addiction levels, and a person could be considered "hooked" on relationships (or on a particular person). This would put love addiction at the extreme end of the spectrum.
None of this is to say that the authors think that love is bad for you just because it can resemble an addiction. Love addiction is not the same as cocaine addiction at the neurological level: important differences, like how long it takes for the desire for another "hit" to occur, do exist. Rather, the authors see this as an opportunity to reconsider our approach to addiction in general and to think about how we can help the heartsick when they just can't seem to get over their last relationship.
Is "love addiction" a treatable disorder?
Hypothetically, a neurological basis for an addiction to love could point toward interventions that "correct" for it. If the narrow view of addiction is accurate, perhaps some people will be able to seek treatment for love addiction in the same way that others seek help to quit smoking. If the broad view of addiction is correct, the treatment of love addiction would be unlikely as it may be difficult to properly identify where the cutoff of acceptability on a spectrum should be.
Either way, since love is generally held in high regard by all cultures and doesn't quite seem to be in the same category as a bad cocaine habit in terms of social undesirability, the authors doubt we'll be treating anyone for "love addiction" anytime soon.
A brief passage from a recent UN report describes what could be the first-known case of an autonomous weapon, powered by artificial intelligence, killing in the battlefield.