Posts Tagged ‘hormones’
more oxytocin fantasies: an interminable conversation 3
not sure if this measures a significant difference
Canto: So, as it turns out, the bonobo-oxytocin connection is all the rage on the internet. I mean, there are at least two articles on it. Here’s a quote from a PubMed article called ‘Divergent effects of oxytocin on eye contact in bonobos and chimpanzees’:
Previous studies have shown that bonobos and chimpanzees, humans’ two closest relatives, demonstrate considerable behavioral differences, including that bonobos look more at others’ eyes than chimpanzees. Oxytocin is known to increase attention to another’s eyes in many mammalian species (e.g. dogs, monkeys, and humans), yet this effect has not been tested in any nonhuman great ape species.
Jacinta: Hmm, so how do they know this? Presumably they’ve dosed subjects with oxytocin and measured their eye contact against controls?
Canto: No no, they know that bonobos have more eye contact than chimps, simply from observation. So they might infer from this that bonobos produce more oxytocin naturally than chimps…
Jacinta: So do women produce more oxytocin than men I wonder? I presume women make more eye contact than men.
Canto: Well in this study they dosed both bonobos and chimps with oxytocin, and the effect – more eye contact – was greater in bonobos than chimps. In fact, chimps even tended to avoid eye contact when shown images of conspecifics.
Jacinta: So, it’s a matter of interplay between this hormone/neurotransmitter and social conditioning?
Canto: Maybe, but you’d think that an increase in this supposedly touchy-feely hormone would act against social conditioning. Isn’t this the point of that drug, ecstacy? That it reduces social inhibitions… But presumably nothing is ever so simple. Being poor, I only have access to the abstract of this paper, but another abstract, which looks at the effects of oxytocin and vasopressin on chimps, describes them as neuropeptides, just to confuse matters. The abstract also refers to about a dozen brain regions, as well as specific oxytocin and vasopressin receptors, so it gets pretty complicated.
Jacinta: Okay, vasopressin… from Wikipedia:
Human vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP), or argipressin, is a hormone synthesised from the AVP gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It then travels down the axon terminating in the posterior pituitary, and is released from vesicles into the circulation in response to extracellular hypertonicity (hyperosmolality). AVP has two major functions… etc etc
Canto: Okay thanks for that, let’s stick with oxytocin for now. It’s produced in the hypothalamus, a smallish region buried deep within the brain, just below the larger thalamus and above the even smaller amygdala. It releases and manages a variety of hormones. Brain signals are sent to the hypothalamus, exciting it to release oxytocin and other hormones, which are secreted into the bloodstream by the posterior pituitary gland….
Jacinta: Can you tell me what oxytocin is actually made of? Its structure? The term ‘hormone’ is just a black box to me.
Canto: Okay, here’s a diagram of oxytocin to try and make sense of:
It’s a polypeptide. A peptide is basically an amino acid chain. FYI:
An amino acid is an organic molecule that is made up of a basic amino group (−NH2), an acidic carboxyl group (−COOH), and an organic R group (or side chain) that is unique to each amino acid. The term amino acid is short for α-amino [alpha-amino] carboxylic acid.
Jacinta: So these are coded for, ultimately, by genes?
Canto: Yes, we’re heading backwards here, but each amino acid is encoded by a sequence of three of the four base pairs in our DNA. Anyway oxytocin, among other things is sometimes given to women while in labour. It helps with the contractions apparently. I’ve also heard that the recreational drug ‘ecstasy’, or MDMA, works essentially by releasing oxytocin.
Jacinta: It just so happens I’ve found an interesting 2014 paper published in Neuropsychopharmacology, my new favourite journal, called ‘Effects of MDMA and Intranasal Oxytocin on Social and Emotional Processing’, and here’s a quote from the abstract:
Oxytocin produced small but significant increases in feelings of sociability and enhanced recognition of sad facial expressions. Additionally, responses to oxytocin were related to responses to MDMA with subjects on two subjective measures of sociability. Thus, MDMA increased euphoria and feelings of sociability, perhaps by reducing sensitivity to subtle signs of negative emotions in others. The present findings provide only limited support for the idea that oxytocin produces the prosocial effects of MDMA.
Canto: That is interesting. If that finding can be replicated, I’d say forget the MDMA, dose people with oxytocin. A small but significant increase in feelings of sociability might just be enough to transform our human world.
Jacinta: Hmmm. Small but significant – that sounds a mite contradictory.
Canto: Not the same as significantly small. That slightly significant dose, administered to Messrs Pudding and Pingpong and their enablers, might’ve saved the lives of many Ukrainians, Uyghurs and advocates of multiculturalism, democracy, feminism and other wild and woolly notions. And it doesn’t really transform characters, it just softens their edges.
Jacinta: Yes it’s a nice fantasy – more productive than butchering the butchers, a fantasy I occasionally indulge in. But not workable really.
Canto: Why not? We dosed petrol with lead, and look at how that worked out. It certainly had an effect. In Japan they still use radium baths (at very low levels) for health purposes, even claiming it as a cure for cancer. I’m not sure if oxytocin baths can ever be a thing, but if so I’m sure there will be early adopters.
Jacinta: Well, it’s good to think positively. Oxytocin is often thought of as a bonding hormone between mother and child. The key would be to ensure it facilitates a more general bonding: to cause Mr Pingpong, for example, to see Uyghur, Tibetan, Yi, Limi, and all the other non-Han ethnicities in China as his sisters – or lovers even, revolting as that would be to those peoples.
Canto: Better than being their oppressors and exterminators.
Jacinta: Slightly. But I wonder, quite seriously, if, assuming such a dose of bonding could be effectuated, we could still function as the sometimes rational, problem-solving, highly creative species we indubitably are. Would there be a price to pay for all that oxytocin? And how would this affect all those other hormones and neurotransmitters and all their myriad effects? Humans are notorious for causing extra problems with their solutions, e.g lead, DDT, etc etc.
Canto: Well, there’s no need to worry about the fallout from this solution as yet. I just googled Putin and oxytocin together and came up empty. Obviously we’re way ahead of the curve.
Jacinta: Haha, it’s not a curve these days, it’s a pivot. Get with the program!
References
https://pubmed.ncbi.nlm.nih.gov/33388536/
https://www.yourhormones.info/hormones/oxytocin/
https://www.acs.org/content/acs/en/molecule-of-the-week/archive/o/oxytocin.html
https://www.britannica.com/science/amino-acid
https://www.wsj.com/articles/BL-JRTB-11551
on love and hormones
The subversive family, a book written by Ferdinand Mount some 40 years ago, argues that the basic family unit, with two or, more rarely, three generations housed together, is indeed more basic than a great many critics allow, and that marriage based on mutual attraction has been more common throughout human history than many historians claim. However that may be, he makes no mention of prehistory, by which I mean the long period of human, and early hominid, existence, before the invention of writing.
What interests me is the nature of sexual relationships during that period, and that nature is hardly likely to have been static. Clearly, marrying is a ceremonial act, which requires a certain level of sophistication. It is apparently intended to ‘tie the knot’, to formalise two persons’ commitment to each other, a commitment expected to be lifelong. Ideally, this commitment is based on love.
It’s interesting that many bird species are monogamous. They stay together, with only the occasional bit on the side, build nests together, share the feeding and teaching of the kids and so on. We talk of love-birds, we love the willow pattern tale, but do we really think these birds love each other? Probably not, because we like to reserve this state of being for humans.
This human specialness thing is eroding though. Dogs mourn their human owners. Elephants grieve over their companions and their children. The more we look at complex social species, the more we find evidence of deep feeling which we may or may not call love, though to call it something other than love would seem insensitive.
But marriage, freely entered into, is about romantic love, and that, some say, is singularly human. Others, of course, say romantic love is a myth, a mixture of hormones and psychology that doesn’t last, though the commitment might continue after the passion is spent, especially where children are involved.
This monogamous arrangement has proved effective for the raising of offspring, in humans as well as in swans, cranes and eagles, and in prairie voles, Azara’s night monkeys and a few other mammalian species. However other complex social animals, such as elephants, dolphins and chimps, are not monogamous, and in fact only about 3% of mammals practice monogamy, and they still manage to raise their young just fine. I have a special interest in bonobos, our closest living relatives, on a par with chimps. They are highly sexualised, yet manage to avoid getting pregnant more than is needful. Females dominate in spite of sexual dimorphism which favours males. Are bonobos, Pan paniscus, a more loving species than Homo sapiens? I leave aside our species’ predilection for aggression and warfare, I’m considering the comparison in times of relatively peace for both species. It is probably impossible to make such a comparison, social contexts are perhaps too different, and bonobos are an endangered species, and quite difficult to study in the wild. As to human apes, it seems that in our human history, which dates back to the development of writing as an effective information and communication tool, we have been almost universally patriarchal and monogamous. But this takes us back only a few thousand years. Our species is at most about 300,000 years old – there’s a lot of debate about this – and tracing our ancestry back to its connection with the bonobo-chimp line has been problematic. There’s also the question of the connection between monogamy and romantic, exclusivist love. For example, it has been found that monogamous prairie voles mate exclusively for life, with the first ready member of the opposite sex they encounter. Clearly this isn’t about romance or conscious decision-making. It will be argued that it is preposterous to compare humans with prairie voles, but from a biological perspective, perhaps not so much. We often talk of ‘love at first sight’ and ‘I don’t know what hit me’ (sometimes with regret). There is no doubt that this sort of immediate sexual attraction can largely be explained by biochemistry. Monogamy in general appears to involve an interplay of hormonal and cultural effects.
Dr Helen Fisher, an anthropologist and research fellow at the Kinsey Institute and Rutgers University, separates romantic love into three parts – lust, attraction and attachment. To summarise, doubtless too briefly, the hormonal effects here, the sex hormones testosterone and, to a lesser extent, oestrogen play a predominant role in increasing libido, or lustful sensations. The hypothalamus stimulates production of these hormones by the ovaries and testes. Testosterone, it should be emphasised, is not a ‘male’ hormone. It produces a variety of effects in both sexes. Attraction is a more complex, more conscious elaboration of lust. It may involve some weighing up of the costs and benefits of particular lustful feelings, though generally under the ‘sway’ of lust. The brain areas involved include the hippocampus, hypothalamus, and anterior cingulate cortex. The activation of these regions tend to increase trust in the object of lust and to inhibit defensive behaviour and anxiety. The hormones dopamine and norepinephrine (aka noradrenaline), which create a sense of euphoria, the sense of ‘being in love’, with its sleeplessness and obsessiveness, will have obviously differential effects depending on the object of attraction’s response to the person attracted. Feelings of attraction also appear to reduce serotonin levels, which help regulate appetite and mood.
Attachment, not surprisingly, is the most complex, conscious and culturally influenced of these three stages. It’s quite a bit cooler (temperature-wise) than the other two, and extends often to other connections, such as friends and family. The hormones most involved in this stage, or state, are vasopressin and oxytocin. Interestingly, those prairie voles mentioned earlier differ greatly from their promiscuous cousins, montane voles, in that they express far more of these two hormones. When these hormones are blocked by researchers, prairie voles turn promiscuous. It would of course be depressingly reductionist to describe attachment, and the other states, as well as their more negative features, such as jealousy, possessiveness and emotional dependence, in purely hormonal terms, but we need to understand, and so to positively change a world of human aggression and thuggery, so prominently displayed on the world stage today, to one a little more bonoboesque, while still preserving the best of our humanity – our inventiveness and our curiosity. Understanding how our hormones affect us is a good start.
References
https://www.ckn.org.au/content/cupid’s-chemical-addiction-–-science-love
Ferdinand Mount, The subversive family, 1981
Robert Sapolsky, Behave, 2017
https://journals.sagepub.com/doi/pdf/10.1177/0265407511431055