Accueil
https://www.deanburnett.com/
https://fr.1lib.fr/book/3506379/e3f215
"What makes anyone happy ? Why are different people made happy by different things, and at different times ? What’s the point of happiness ? Is there one ?"
"MRI stands for Magnetic Resonance Imaging, a complex hi-tech procedure which uses powerful magnetic fields, radio waves and several other types of tech-wizardry to produce very detailed images of the inside of a live human body, revealing things like broken bones, soft tissue tumours, liver lesions and alien parasites (probably).
But more attentive readers will have noticed that I referred to fMRI. The ‘f’ is important. It stands for ‘functional’, so it’s functional magnetic resonance imaging. This means that the same approach used to look at the structure of the body can be adapted to observe the activity of the working brain, allowing us to witness the interactions occurring between the countless neurons that make up our brains. It may not sound that impressive, but this activity is essentially the basis of our mind and consciousness, in much the same way that individual cells make up our body (cells combine in complex ways to form tissues, which combine in complex ways to form organs, which combine to form one functioning entity that is you). Scientifically speaking, this is a fairly big deal."
"We need to know precisely where in the brain happiness comes from. Which part produces it, which region underpins it, which area recognises the occurrence of happiness-inducing events ? For this, you have to look inside a happy brain, and see what’s happening. It’s no simple task, and to have any hope of doing it, you need sophisticated neuroimaging techniques, like fMRI."
"I live a very short distance from CUBRIC, the Cardiff University Brain Research Imaging Centre, where I volunteered for all those studies. It was being built as I completed my PhD at the Cardiff Psychology School, and was opened just after I left. This timing seemed a bit mean-spirited if I’m honest, like the whole institution had said, ‘Is he gone? Good, now we can break out the good stuff.’
CUBRIC is an excellent place to go for the latest cutting-edge investigations into the workings of the human brain."
"If you want to know which bit of the brain is responsible for happiness, consider what counts as a ‘bit’ of the brain. Although it’s often thought of as a single (surprisingly ugly) object, it can be broken down into a vast number of individual components.† The brain has two hemispheres (left and right), made up of four distinct lobes (frontal, parietal, occipital, temporal), each of which is composed of numerous different regions and nuclei. These are made up of brain cells called neurons and numerous other vital support cells called glia, which keep things functioning. Each cell is essentially a complicated arrangement of chemicals. So you could say that, like most organs and living objects, the brain is a big lump of chemicals. Chemicals arranged in breathtakingly complex forms, but chemicals nonetheless.
In fairness, we could break it down even further. Chemicals are made of atoms, which are in turn made of electrons, protons and neutrons, which are in turn made of gluons, and so on. You end up getting into complex particle physics as you delve deeper into the fundamental makeup of matter itself. However, there are certain chemicals the brain uses for purposes beyond basic physical structure, meaning they have a more ‘dynamic’ role to play than just being the building blocks of cells.
These chemicals are neurotransmitters, and they play key roles in the functioning of the brain. If you’re looking for the most simple, fundamental elements of the brain that still have profound impacts on how we think and feel, these chemical neurotransmitters would be them. The brain is essentially a huge and incredibly complicated mass of neurons, and everything the brain does is dependent on, and the result of, patterns of activity generated in these neurons. A single electrochemical signal, a pulse known as an ‘action potential’, travels along a neuron and, when it reaches the end, is transferred to the next one in line, until it reaches where it’s meant to go. Think of it like an amp travelling along a circuit from a power station to your bedside lamp. It’s quite an impressive distance for something so insubstantial to travel, but it’s so common we barely even consider it.
The pattern and rate of these signals, these action potentials, can vary enormously, and the chains of neurons relaying them can be incredibly long and branch off almost endlessly, allowing for billions of patterns, trillions of possible calculations, supported by connections between almost every dedicated region of the human brain. That’s what makes the brain as powerful as it is.
Stepping back slightly, the point at which the signal is transferred from one neuron to the next is incredibly important. This occurs at synapses, the point where two neurons meet. However, and here’s where it gets slightly strange, there’s no significant physical contact between the two neurons; the synapse itself is the gap between them, not a solid object. So how does a signal travel from one neuron to the other if they don’t touch ?
Neurotransmitters is how. The signal arrives at the terminus of the first neuron in the chain, and this causes the neuron to squirt neurotransmitters into the synapse. They then interact with dedicated receptors in the second neuron, and this causes the signal to be induced again in that neuron, and it’s then relayed along to the next one in line. And on it goes.
Think of it like an important message, sent by the scouts of a medieval army to the commanders back at headquarters. The message is on a piece of paper, being carried on foot by a soldier. He reaches a river, but needs to get the message to the camp on the other side. So, he ties it to an arrow and fires it across, where another soldier can pick it up and carry it further along the journey back to headquarters. Neurotransmitters are like that arrow.
The brain uses a wide variety of neurotransmitters, and the specific neurotransmitter used has a palpable effect on the activity and behaviour of the next neuron. That’s assuming the next neuron has the relevant receptors embedded in its membrane; neurotransmitters only work if they can find a compatible receptor to interact with, a bit like a key only working for a specific lock, or series of locks. To go back to the soldier metaphor, the message is encrypted so only those from the same army will be able to read it.
There’s also a wide variety of orders the message could contain: attack, retreat, rally forces, defend the left flanks, and so forth. Neurotransmitters are similarly flexible. Some transmitters increase signal strength, some reduce it, some stop it, some cause different responses altogether. These are cells we’re talking about, not inert electrical cables; they’re diverse in how they react. Because of the diversity offered by this setup, the brain often uses specific neurotransmitters in certain areas to fulfil certain roles and functions. So, with this in mind, is it possible that there is a neurotransmitter, a chemical, responsible for producing happines ? Surprising as it may seem, this isn’t that far-fetched. There are even several candidates for such a thing."
"Dopamine is an obvious one. Dopamine is a neurotransmitter that fulfils a wide variety of functions in the brain, but one of the most familiar and established is its role in reward and pleasure. Dopamine is the neurotransmitter underpinning all activity in the mesolimbic reward pathway in the brain, sometimes called the dopaminergic reward pathway in acknowledgement of this. Whenever the brain recognises that you’ve done something it approves of (drunk water while thirsty, escaped a perilous situation, been sexually intimate with a partner, etc.), it typically rewards this behaviour by causing you to experience brief but often intense pleasure triggered by the release of dopamine. And pleasure makes you happy, right? The dopaminergic reward pathway is the brain region responsible for this process.
There’s also evidence to suggest that dopamine release is affected by how surprising a reward or experience is. The more unexpected something is, the more we enjoy it, and this seems due to how much dopamine the brain deploys. Expected rewards correspond with an initial dopamine surge, which then tails off. But unexpected rewards correspond with an increased level of dopamine release for a longer period after the reward is experienced.
To put this in a real-world context, if you see that money has arrived in your account on payday, that’s an anticipated reward. Conversely, finding £20 in an old pair of trousers, that’s unexpected. The latter is much less money, but it’s more rewarding, because it wasn’t expected. And this, as far as we can see, causes a greater dopamine release. Similarly, absence of an expected reward (e.g. your pay isn’t in your bank account on payday) seems to cause a substantial drop in dopamine. Such things are unpleasant and stressful. So, obviously, dopamine is integral to our ability to enjoy things.
But as mentioned previously, supporting pleasure and reward is just one of dopamine’s many and varied roles and functions across the brain. Perhaps other chemicals have more specific roles in inducing pleasure ?
Of course, endorphin neurotransmitters are the ‘big daddy’ of pleasure-causing chemicals. Whether they are released from gorging on chocolate or due to the rush of sex, endorphins provide that oh-so-wonderful intense giddy warm sensation that permeates your very being.
The potency of endorphins should not be underestimated. Powerful opiate drugs like heroin and morphine work because they trigger the endorphin receptors in our brains and bodies. They’re obviously pleasurable (hence the alarming number of people who use them), but these drugs are also clearly debilitating. Someone in the grip of an intense opiate ‘high’ isn’t much good for anything other than staring into space and occasionally drooling. And some estimates suggest that heroin is only 20 per cent as potent as natural endorphins! We have substances five times as powerful as the most intoxicating narcotic just hanging around in our brains – it’s a wonder we get anything done at all.
While it’s bad news for pleasure seekers, it’s good news for the functioning of the human race to hear that the brain uses endorphins very carefully. Most typically, the brain releases endorphins in response to serious pain and stress. A good example of both is childbirth.
Mothers use many terms to describe childbirth – ‘miraculous’, ‘incredible’, ‘amazing’, and so on – but ‘enjoyable’ is rarely among them. And yet despite the extreme physical demands it places on a woman’s body, they get through it, and often do it again. This is because human women have evolved many different adaptations to facilitate childbirth, and one of these is the build-up and release of endorphins as it progresses.
The brain deploys endorphins to dampen the pain and stop it from reaching heart-stopping levels (which can happen). This could also contribute to the almost deliriously happy state women experience the moment the baby is born (although that’s possibly just relief). Thanks to endorphins, childbirth, no matter how gruelling it is, could be worse.
That’s one extreme example. There are other ways to expose yourself to enough pain and stress to trigger an endorphin release (like by being a man and telling mothers that childbirth could be worse). Putting your body through other sorts of physical extremes, for example. People who do marathons report the ‘runner’s high’, an incredibly pleasurable rush that occurs when your body is physically taxed enough for the brain to break out the big guns and drown out all the aches and pains. It could therefore be argued that the function of endorphins isn’t to induce pleasure, but to prevent pain. Maybe labelling endorphins as ‘pleasure inducing’ is like describing a fire engine as ‘a machine that makes things wet’; yes, it does that, but no, that’s not what it’s for.
Some argue that this agony-reduction function only applies to detectable levels of endorphins, where their action is noticeable to the person. There’s evidence to suggest that at a lower concentration endorphins play a more basic role, helping regulate behaviour and task management. The endorphin system, via complex interactions with the neurological systems that regulate stress and motivation, helps us know when something is ‘done’. An important task needs doing and you get stressed ; you complete the task and the brain releases a subtle dose of endorphins so we feel ‘it’s done, let’s move on’. Not exactly producing pleasure, but helpful and reducing stress, thus contributing to wellbeing and happiness. This is further evidence of the preventative function of endorphins in maintaining happiness.
One problem with both the dopamine and endorphin explanations is they assume ‘happiness’ is the same as ‘pleasure’. While it’s certainly possible (normal, even) to be happy while experiencing pleasure, to be truly happy surely requires a lot more than that. Life is more than just a series of euphoric moments. Happiness is also about contentment, satisfaction, love, relationships, family, motivation, wellbeing, and many other words found in Facebook memes. Could there be a chemical that supports this more ‘profound’ stuff ? Maybe.
One contender would be oxytocin. Oxytocin has an unusual reputation, often being described as the ‘love’ hormone, or the ‘cuddle’ hormone. Despite what much of the modern media would suggest, humans are a very friendly species, and usually actively need social bonds with others in order to be happy. The closer and more intense these bonds, the more important they are. The bonds between lovers, relatives, very close friends, tend to make people happy over the long term. And oxytocin is apparently integral for these.
Going back to the process of childbirth again, oxytocin’s most established role is as a chemical released in high doses during labour and breastfeeding. It is key for this most fundamental of meetings between individuals – it causes the immediate and intense bonding between mother and baby, is present in breast milk, and induces lactation. However, oxytocin has since been implicated in a much wider variety of situations: sexual arousal and responses, stress, social interaction, fidelity, and no doubt much more.
This has a number of weird consequences. For instance, oxytocin is important for forming and enhancing social bonds but it is also released during sexual intercourse. This may be why the oft-referenced ‘friends with benefits’ arrangement (where two friends opt to be physically intimate without any stifling relationship/commitment) is so notoriously difficult to maintain. Thanks to oxytocin, sexual interaction can fundamentally alter your perception of your partner, changing purely physical attraction into genuine affection and longing. Oxytocin is what’s ‘making the love’ during lovemaking.
And while oxytocin affects women more than men, it does still have potent effects on men; for instance, one study showed that, when dosed with oxytocin, men in relationships will keep more of a distance between themselves and attractive women in a social context than single men do. The conclusion drawn here is that increased oxytocin makes men more committed to their partner, making them more aware of how their actions might impact on them, meaning they’d be warier of interacting with unfamiliar attractive women, especially when others are there to see it. Basically, it can be argued that oxytocin strengthens existing romantic bonds. But it doesn’t create them per se, hence single men don’t show similar behaviour.
There is far more that could be said, but the point is that oxytocin is vital for the human brain to experience love, intimacy, trust, friendship and social bonding. All but the most cynical souls would agree that such things are crucial for lasting happiness. So, therefore, is oxytocin responsible for happiness ?
Not quite. As with most things, oxytocin has a down side. For instance, increasing your social bonds with an individual or a group can increase your hostility to anyone outside that bond. One study found that men dosed with oxytocin were much quicker to ascribe negative traits to anyone not from their culture or ethnic background. Or, to put it another way, oxytocin makes you racist. If racism is integral to happiness, then I’m not sure humans deserve it.
It doesn’t have to be so extreme though; you’ve probably witnessed someone (or even been that someone) experiencing bitter jealousy and resentment, even hatred, when the object of their affection is seen to interact in an overly friendly way with someone else. The fact that ‘crimes of passion’ exist shows just how potent and destructive this reaction can be. There are many ways to describe someone gripped by jealous rage or paranoid suspicion; ‘happy’ isn’t one of them. Oxytocin may be crucially important for social bonding, but not all social bonding leads to happiness. It can, in fact, lead to the opposite.
Perhaps this whole approach is too far removed ? Pleasure and intimacy could be said to lead to happiness, so any chemical that gives rise to these things is only indirectly ‘causing’ happiness. Is there any chemical that makes us happy directly ?
Serotonin may do this. It’s a neurotransmitter used in a wide variety of neurological processes, so has a diverse range of roles, such as enabling sleep, controlling digestion, and, most relevantly, regulating mood.
Serotonin appears to be vital for allowing us to achieve a good mood, aka ‘be happy’. The most prescribed antidepressants available today work by increasing the levels of serotonin available in the brain. Current wisdom argues that depression arises due to reduced levels of serotonin, and this is something that should be fixed.
Prozac and similar medications are classed as SSRIs, or selective serotonin reuptake inhibitors. After being released into the synapses to relay signals, serotonin isn’t broken down or destroyed, instead it is re-absorbed by the neurons. SSRIs basically stop this re-absorption from occurring. The result is that rather than a quick burst of activity in the next neuron produced by a brief appearance of serotonin in the synapse, this activity is prolonged because the serotonin hangs around, intact, constantly triggering the relevant receptors. You know when your toaster gets old and keeps popping the bread out before it’s done, so you have to leave it in for longer to get it how you like it ? It’s a bit like that. And this treats depression. Therefore, serotonin is obviously a chemical that causes happiness, right ?
Not right. The fact is, nobody really knows (yet) what it is that the increase of serotonin is actually doing in the brain. If it’s simply the case that there’s insufficient serotonin to produce a state of happiness, then that should be an easy fix. However, given the speed at which our metabolisms and brains work, SSRIs increase serotonin levels pretty much immediately. And yet, most SSRIs take weeks of regular doses to be effective. So, clearly it isn’t just the serotonin itself which is responsible for a happy mood, it must be having an indirect effect on something else.
Perhaps the real problem is with the approach; you can attribute powerful neurological properties to simple molecules all you like, it doesn’t mean that’s how things work. If you look around, you can find many an article or column explaining how to hack into your ‘happy hormones’ or similar, claiming that a few simple diet and exercise techniques can raise the levels of the relevant chemicals in your brain, resulting in lasting contentment and enjoyment of life. Sadly, this is severe oversimplification of incredibly complex processes.
Essentially, it seems that trying to pin happiness on a specific chemical is the wrong approach. They’re involved, but not a cause. A £50 note is valuable, and is made of paper. But it’s not valuable because it’s made of paper. And so it may be that the chemicals described here are to happiness what paper is to money; they allow it to exist, but their role is mostly incidental."
-Dean Burnett, The Happy Brain: The Science of Where Happiness Comes from, and Why, HarperCollins Publishers, 2019 (2018 pour la première édition), 352 pages.
https://fr.1lib.fr/book/3506379/e3f215
"What makes anyone happy ? Why are different people made happy by different things, and at different times ? What’s the point of happiness ? Is there one ?"
"MRI stands for Magnetic Resonance Imaging, a complex hi-tech procedure which uses powerful magnetic fields, radio waves and several other types of tech-wizardry to produce very detailed images of the inside of a live human body, revealing things like broken bones, soft tissue tumours, liver lesions and alien parasites (probably).
But more attentive readers will have noticed that I referred to fMRI. The ‘f’ is important. It stands for ‘functional’, so it’s functional magnetic resonance imaging. This means that the same approach used to look at the structure of the body can be adapted to observe the activity of the working brain, allowing us to witness the interactions occurring between the countless neurons that make up our brains. It may not sound that impressive, but this activity is essentially the basis of our mind and consciousness, in much the same way that individual cells make up our body (cells combine in complex ways to form tissues, which combine in complex ways to form organs, which combine to form one functioning entity that is you). Scientifically speaking, this is a fairly big deal."
"We need to know precisely where in the brain happiness comes from. Which part produces it, which region underpins it, which area recognises the occurrence of happiness-inducing events ? For this, you have to look inside a happy brain, and see what’s happening. It’s no simple task, and to have any hope of doing it, you need sophisticated neuroimaging techniques, like fMRI."
"I live a very short distance from CUBRIC, the Cardiff University Brain Research Imaging Centre, where I volunteered for all those studies. It was being built as I completed my PhD at the Cardiff Psychology School, and was opened just after I left. This timing seemed a bit mean-spirited if I’m honest, like the whole institution had said, ‘Is he gone? Good, now we can break out the good stuff.’
CUBRIC is an excellent place to go for the latest cutting-edge investigations into the workings of the human brain."
"If you want to know which bit of the brain is responsible for happiness, consider what counts as a ‘bit’ of the brain. Although it’s often thought of as a single (surprisingly ugly) object, it can be broken down into a vast number of individual components.† The brain has two hemispheres (left and right), made up of four distinct lobes (frontal, parietal, occipital, temporal), each of which is composed of numerous different regions and nuclei. These are made up of brain cells called neurons and numerous other vital support cells called glia, which keep things functioning. Each cell is essentially a complicated arrangement of chemicals. So you could say that, like most organs and living objects, the brain is a big lump of chemicals. Chemicals arranged in breathtakingly complex forms, but chemicals nonetheless.
In fairness, we could break it down even further. Chemicals are made of atoms, which are in turn made of electrons, protons and neutrons, which are in turn made of gluons, and so on. You end up getting into complex particle physics as you delve deeper into the fundamental makeup of matter itself. However, there are certain chemicals the brain uses for purposes beyond basic physical structure, meaning they have a more ‘dynamic’ role to play than just being the building blocks of cells.
These chemicals are neurotransmitters, and they play key roles in the functioning of the brain. If you’re looking for the most simple, fundamental elements of the brain that still have profound impacts on how we think and feel, these chemical neurotransmitters would be them. The brain is essentially a huge and incredibly complicated mass of neurons, and everything the brain does is dependent on, and the result of, patterns of activity generated in these neurons. A single electrochemical signal, a pulse known as an ‘action potential’, travels along a neuron and, when it reaches the end, is transferred to the next one in line, until it reaches where it’s meant to go. Think of it like an amp travelling along a circuit from a power station to your bedside lamp. It’s quite an impressive distance for something so insubstantial to travel, but it’s so common we barely even consider it.
The pattern and rate of these signals, these action potentials, can vary enormously, and the chains of neurons relaying them can be incredibly long and branch off almost endlessly, allowing for billions of patterns, trillions of possible calculations, supported by connections between almost every dedicated region of the human brain. That’s what makes the brain as powerful as it is.
Stepping back slightly, the point at which the signal is transferred from one neuron to the next is incredibly important. This occurs at synapses, the point where two neurons meet. However, and here’s where it gets slightly strange, there’s no significant physical contact between the two neurons; the synapse itself is the gap between them, not a solid object. So how does a signal travel from one neuron to the other if they don’t touch ?
Neurotransmitters is how. The signal arrives at the terminus of the first neuron in the chain, and this causes the neuron to squirt neurotransmitters into the synapse. They then interact with dedicated receptors in the second neuron, and this causes the signal to be induced again in that neuron, and it’s then relayed along to the next one in line. And on it goes.
Think of it like an important message, sent by the scouts of a medieval army to the commanders back at headquarters. The message is on a piece of paper, being carried on foot by a soldier. He reaches a river, but needs to get the message to the camp on the other side. So, he ties it to an arrow and fires it across, where another soldier can pick it up and carry it further along the journey back to headquarters. Neurotransmitters are like that arrow.
The brain uses a wide variety of neurotransmitters, and the specific neurotransmitter used has a palpable effect on the activity and behaviour of the next neuron. That’s assuming the next neuron has the relevant receptors embedded in its membrane; neurotransmitters only work if they can find a compatible receptor to interact with, a bit like a key only working for a specific lock, or series of locks. To go back to the soldier metaphor, the message is encrypted so only those from the same army will be able to read it.
There’s also a wide variety of orders the message could contain: attack, retreat, rally forces, defend the left flanks, and so forth. Neurotransmitters are similarly flexible. Some transmitters increase signal strength, some reduce it, some stop it, some cause different responses altogether. These are cells we’re talking about, not inert electrical cables; they’re diverse in how they react. Because of the diversity offered by this setup, the brain often uses specific neurotransmitters in certain areas to fulfil certain roles and functions. So, with this in mind, is it possible that there is a neurotransmitter, a chemical, responsible for producing happines ? Surprising as it may seem, this isn’t that far-fetched. There are even several candidates for such a thing."
"Dopamine is an obvious one. Dopamine is a neurotransmitter that fulfils a wide variety of functions in the brain, but one of the most familiar and established is its role in reward and pleasure. Dopamine is the neurotransmitter underpinning all activity in the mesolimbic reward pathway in the brain, sometimes called the dopaminergic reward pathway in acknowledgement of this. Whenever the brain recognises that you’ve done something it approves of (drunk water while thirsty, escaped a perilous situation, been sexually intimate with a partner, etc.), it typically rewards this behaviour by causing you to experience brief but often intense pleasure triggered by the release of dopamine. And pleasure makes you happy, right? The dopaminergic reward pathway is the brain region responsible for this process.
There’s also evidence to suggest that dopamine release is affected by how surprising a reward or experience is. The more unexpected something is, the more we enjoy it, and this seems due to how much dopamine the brain deploys. Expected rewards correspond with an initial dopamine surge, which then tails off. But unexpected rewards correspond with an increased level of dopamine release for a longer period after the reward is experienced.
To put this in a real-world context, if you see that money has arrived in your account on payday, that’s an anticipated reward. Conversely, finding £20 in an old pair of trousers, that’s unexpected. The latter is much less money, but it’s more rewarding, because it wasn’t expected. And this, as far as we can see, causes a greater dopamine release. Similarly, absence of an expected reward (e.g. your pay isn’t in your bank account on payday) seems to cause a substantial drop in dopamine. Such things are unpleasant and stressful. So, obviously, dopamine is integral to our ability to enjoy things.
But as mentioned previously, supporting pleasure and reward is just one of dopamine’s many and varied roles and functions across the brain. Perhaps other chemicals have more specific roles in inducing pleasure ?
Of course, endorphin neurotransmitters are the ‘big daddy’ of pleasure-causing chemicals. Whether they are released from gorging on chocolate or due to the rush of sex, endorphins provide that oh-so-wonderful intense giddy warm sensation that permeates your very being.
The potency of endorphins should not be underestimated. Powerful opiate drugs like heroin and morphine work because they trigger the endorphin receptors in our brains and bodies. They’re obviously pleasurable (hence the alarming number of people who use them), but these drugs are also clearly debilitating. Someone in the grip of an intense opiate ‘high’ isn’t much good for anything other than staring into space and occasionally drooling. And some estimates suggest that heroin is only 20 per cent as potent as natural endorphins! We have substances five times as powerful as the most intoxicating narcotic just hanging around in our brains – it’s a wonder we get anything done at all.
While it’s bad news for pleasure seekers, it’s good news for the functioning of the human race to hear that the brain uses endorphins very carefully. Most typically, the brain releases endorphins in response to serious pain and stress. A good example of both is childbirth.
Mothers use many terms to describe childbirth – ‘miraculous’, ‘incredible’, ‘amazing’, and so on – but ‘enjoyable’ is rarely among them. And yet despite the extreme physical demands it places on a woman’s body, they get through it, and often do it again. This is because human women have evolved many different adaptations to facilitate childbirth, and one of these is the build-up and release of endorphins as it progresses.
The brain deploys endorphins to dampen the pain and stop it from reaching heart-stopping levels (which can happen). This could also contribute to the almost deliriously happy state women experience the moment the baby is born (although that’s possibly just relief). Thanks to endorphins, childbirth, no matter how gruelling it is, could be worse.
That’s one extreme example. There are other ways to expose yourself to enough pain and stress to trigger an endorphin release (like by being a man and telling mothers that childbirth could be worse). Putting your body through other sorts of physical extremes, for example. People who do marathons report the ‘runner’s high’, an incredibly pleasurable rush that occurs when your body is physically taxed enough for the brain to break out the big guns and drown out all the aches and pains. It could therefore be argued that the function of endorphins isn’t to induce pleasure, but to prevent pain. Maybe labelling endorphins as ‘pleasure inducing’ is like describing a fire engine as ‘a machine that makes things wet’; yes, it does that, but no, that’s not what it’s for.
Some argue that this agony-reduction function only applies to detectable levels of endorphins, where their action is noticeable to the person. There’s evidence to suggest that at a lower concentration endorphins play a more basic role, helping regulate behaviour and task management. The endorphin system, via complex interactions with the neurological systems that regulate stress and motivation, helps us know when something is ‘done’. An important task needs doing and you get stressed ; you complete the task and the brain releases a subtle dose of endorphins so we feel ‘it’s done, let’s move on’. Not exactly producing pleasure, but helpful and reducing stress, thus contributing to wellbeing and happiness. This is further evidence of the preventative function of endorphins in maintaining happiness.
One problem with both the dopamine and endorphin explanations is they assume ‘happiness’ is the same as ‘pleasure’. While it’s certainly possible (normal, even) to be happy while experiencing pleasure, to be truly happy surely requires a lot more than that. Life is more than just a series of euphoric moments. Happiness is also about contentment, satisfaction, love, relationships, family, motivation, wellbeing, and many other words found in Facebook memes. Could there be a chemical that supports this more ‘profound’ stuff ? Maybe.
One contender would be oxytocin. Oxytocin has an unusual reputation, often being described as the ‘love’ hormone, or the ‘cuddle’ hormone. Despite what much of the modern media would suggest, humans are a very friendly species, and usually actively need social bonds with others in order to be happy. The closer and more intense these bonds, the more important they are. The bonds between lovers, relatives, very close friends, tend to make people happy over the long term. And oxytocin is apparently integral for these.
Going back to the process of childbirth again, oxytocin’s most established role is as a chemical released in high doses during labour and breastfeeding. It is key for this most fundamental of meetings between individuals – it causes the immediate and intense bonding between mother and baby, is present in breast milk, and induces lactation. However, oxytocin has since been implicated in a much wider variety of situations: sexual arousal and responses, stress, social interaction, fidelity, and no doubt much more.
This has a number of weird consequences. For instance, oxytocin is important for forming and enhancing social bonds but it is also released during sexual intercourse. This may be why the oft-referenced ‘friends with benefits’ arrangement (where two friends opt to be physically intimate without any stifling relationship/commitment) is so notoriously difficult to maintain. Thanks to oxytocin, sexual interaction can fundamentally alter your perception of your partner, changing purely physical attraction into genuine affection and longing. Oxytocin is what’s ‘making the love’ during lovemaking.
And while oxytocin affects women more than men, it does still have potent effects on men; for instance, one study showed that, when dosed with oxytocin, men in relationships will keep more of a distance between themselves and attractive women in a social context than single men do. The conclusion drawn here is that increased oxytocin makes men more committed to their partner, making them more aware of how their actions might impact on them, meaning they’d be warier of interacting with unfamiliar attractive women, especially when others are there to see it. Basically, it can be argued that oxytocin strengthens existing romantic bonds. But it doesn’t create them per se, hence single men don’t show similar behaviour.
There is far more that could be said, but the point is that oxytocin is vital for the human brain to experience love, intimacy, trust, friendship and social bonding. All but the most cynical souls would agree that such things are crucial for lasting happiness. So, therefore, is oxytocin responsible for happiness ?
Not quite. As with most things, oxytocin has a down side. For instance, increasing your social bonds with an individual or a group can increase your hostility to anyone outside that bond. One study found that men dosed with oxytocin were much quicker to ascribe negative traits to anyone not from their culture or ethnic background. Or, to put it another way, oxytocin makes you racist. If racism is integral to happiness, then I’m not sure humans deserve it.
It doesn’t have to be so extreme though; you’ve probably witnessed someone (or even been that someone) experiencing bitter jealousy and resentment, even hatred, when the object of their affection is seen to interact in an overly friendly way with someone else. The fact that ‘crimes of passion’ exist shows just how potent and destructive this reaction can be. There are many ways to describe someone gripped by jealous rage or paranoid suspicion; ‘happy’ isn’t one of them. Oxytocin may be crucially important for social bonding, but not all social bonding leads to happiness. It can, in fact, lead to the opposite.
Perhaps this whole approach is too far removed ? Pleasure and intimacy could be said to lead to happiness, so any chemical that gives rise to these things is only indirectly ‘causing’ happiness. Is there any chemical that makes us happy directly ?
Serotonin may do this. It’s a neurotransmitter used in a wide variety of neurological processes, so has a diverse range of roles, such as enabling sleep, controlling digestion, and, most relevantly, regulating mood.
Serotonin appears to be vital for allowing us to achieve a good mood, aka ‘be happy’. The most prescribed antidepressants available today work by increasing the levels of serotonin available in the brain. Current wisdom argues that depression arises due to reduced levels of serotonin, and this is something that should be fixed.
Prozac and similar medications are classed as SSRIs, or selective serotonin reuptake inhibitors. After being released into the synapses to relay signals, serotonin isn’t broken down or destroyed, instead it is re-absorbed by the neurons. SSRIs basically stop this re-absorption from occurring. The result is that rather than a quick burst of activity in the next neuron produced by a brief appearance of serotonin in the synapse, this activity is prolonged because the serotonin hangs around, intact, constantly triggering the relevant receptors. You know when your toaster gets old and keeps popping the bread out before it’s done, so you have to leave it in for longer to get it how you like it ? It’s a bit like that. And this treats depression. Therefore, serotonin is obviously a chemical that causes happiness, right ?
Not right. The fact is, nobody really knows (yet) what it is that the increase of serotonin is actually doing in the brain. If it’s simply the case that there’s insufficient serotonin to produce a state of happiness, then that should be an easy fix. However, given the speed at which our metabolisms and brains work, SSRIs increase serotonin levels pretty much immediately. And yet, most SSRIs take weeks of regular doses to be effective. So, clearly it isn’t just the serotonin itself which is responsible for a happy mood, it must be having an indirect effect on something else.
Perhaps the real problem is with the approach; you can attribute powerful neurological properties to simple molecules all you like, it doesn’t mean that’s how things work. If you look around, you can find many an article or column explaining how to hack into your ‘happy hormones’ or similar, claiming that a few simple diet and exercise techniques can raise the levels of the relevant chemicals in your brain, resulting in lasting contentment and enjoyment of life. Sadly, this is severe oversimplification of incredibly complex processes.
Essentially, it seems that trying to pin happiness on a specific chemical is the wrong approach. They’re involved, but not a cause. A £50 note is valuable, and is made of paper. But it’s not valuable because it’s made of paper. And so it may be that the chemicals described here are to happiness what paper is to money; they allow it to exist, but their role is mostly incidental."
-Dean Burnett, The Happy Brain: The Science of Where Happiness Comes from, and Why, HarperCollins Publishers, 2019 (2018 pour la première édition), 352 pages.
