Every study on hormones from the last 40 years has shown conclusive evidence that hormone levels within natural occurring levels has very minimal effect on behavior, emotion and life choices. If you want to find differences between gender, look at chromosomes and their effect. The purpose of hormone is to primarily regulate the reproductive system.
natural occurring levels. A person who injects steroids to create hormone levels with order of magnitude above normal levels is not natural occurring.
If you take a number of people with different aggressiveness (or as most studies do, look at chimps with picking orders), and you find no correlation with hormone. Add 5% more hormone, and you don't get 5% behavior. Pump in larger amount of hormone, and you see exaggeration of existing behavior. Remove all hormone, and you see a decrease behavior, but the behavior doesn't go away. Its regulative.
post-partum depression, menopause, and pregnancy all cause major changes in a person. Hormone levels, since its regulative, also change with those changes. There were for example a study at women with abnormal amount of testosterone (but within the limit of naturally occurring in humans). The first studies from 1970 showed how there was increased crime, increase aggressiveness, changes in sexuality, emotions, and the ability to keep maintain a job. When people tried to reproduce those studies, everything was shown to be false.
To simplify, do you know of any scientific or medical sources that say "hormones (within natural occurring levels) have very minimal effect on emotion" as you claimed earlier?
lets me quote a few different text. The key word that I used was regulative effect.
"Normal estrogen levels vary widely. Large differences are typical in a woman on different days, or between two women on the same day of their cycles. The actual measured level of estrogen doesn't predict emotional disturbances.". (webmd article. not a authoritative but useful as a general summery)
"However, estrogen is not simply a natural "physiological protectant". Some have reported that estrogen administration does not improve mood and even causes fear and anxiety. Therefore, the impact of estrogen on emotion varies and may depend on the individual's current state and the situation. The authors believe that hormones do not exert an absolute and singular effect on the body." (Estrogen Impacts on Emotion: Psychological, Neuroscience and Endocrine Studies)
As an example estrogen effect, it regulated how easy memories of arousals are formed, which also adrenaline happens to do. Both do this for rather logical reasons, ie, to increase or decrease the chance of a similar event to happen again. This can then have an effect of the perception of fearful faces, although the study on mice from 2006 (Jasnow et al) doesn't really give a definitive number on how big impact that has on female mice total emotional state. It is also reported that this effect the perception of pain and the memory of having pain.
"The testosterone increment was associated with detectable but minor mood changes ... Future research should investigate the implications of these minor mood changes."(Effects of Testosterone on Mood, Aggression, and Sexual Behavior in Young Men: A Double-Blind, Placebo-Controlled, Cross-Over Study)
I will stop here. People like to blame hormones and hormone levels to excuse someones behavior. The data I have seen is quite clear the effect is regulative and thus you don't get an cause-and-effect.
Administered hormones are not equivalent to natural hormones (which is a significant problem with HRT).
And those quotes are not quite "hormones (within natural occurring levels) have very minimal effect on emotion".
"the impact of estrogen on emotion varies"
And another quote from the study you quoted (Effects of testosterone on mood, aggression, and sexual behavior in young men: a double-blind, placebo-controlled, cross-over study):
"Increased circulating T was associated with significant increases in anger-hostility from baseline (mean score = 7.48) to wk 2 (mean score = 10.71)"
7.48 to 10.71 doesn't seem like a very minimal change.
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Since you quoted WebMD (perhaps a useful summary) I will as well:
"It's clear that estrogen is closely linked with women's emotional well-being. Depression and anxiety affect women in their estrogen-producing years more often than men or postmenopausal women. Estrogen is also linked to mood disruptions that occur only in women -- premenstrual syndrome, premenstrual dysphoric disorder, and postpartum depression."
And from another article:
"Declining estrogen levels associated with menopause can cause more than those pesky hot flashes. They can also make a woman feel like she is in a constant state of PMS (premenstrual syndrome). Unfortunately, these emotional changes are a normal part of menopause."
"Some of the emotional changes experienced by women undergoing perimenopause or menopause can include: Irritability, Feelings of sadness, Lack of motivation, Anxiety, Aggressiveness, Difficulty concentrating, Fatigue, Mood changes, and Tension."
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Perhaps we can agree.
I'm not sure exactly what you mean by regulative, but I agree that emotions are complicated and hormones are not the only influence, nor is the relationship a simple cause and effect.
On the other hand, there's significant evidence that hormones do effect emotion, including perhaps the most striking example which I somehow forgot earlier: puberty. And their prenatal effect on the structure of the brain.
Would you agree hormones do effect emotions, but aren't the only factor, and the relationship is complicated, unpredictable, and varies between individuals?
I would use the wording of the article, in that hormone is closely linked and associated with certain behavior. There is very little studies (but feel free to provide them) that shows that artificial reduced estrogen will cause a person to get emotional upset.
By regulative I mean that in order to see a major effect, you already need to have a major state. A person with no aggression is not going to get aggressive based on testosterone. A person that is already aggressive will have that aggression regulated if one artificially increasing the circulating testosterone, most often by exaggerating the aggression in a context aware way. For example, a person who has a tendency for road rage won't be more likely to shoot someone, but they might honk the horn more or yell more loudly. Regulative effects don't cause things to happen, but rather modulate what already exist.
Puberty and pregnancy has an other thing in common, in that it both cause changes in the persons neurons. Its speculated the reason that a womans body during pregnancy do this is in order to make it easier form memories and bond with the newborn baby. Its been suggested that some typical pregnancy behaviors is thus a result of those changes to the neurons. I would strongly suspect that hormone levels have a regulative role in facilitating the rate of the changes, but I doubt if measuring the hormone level would be a predictor for how much of a change actually happened.
To bring out an analogy, taxes has an regulative effect on wealth, but its a not a predictor for it. If I selected random individuals over the world and only looked at where they live and how much percent that they pay in taxes, it will tell me nothing about who is rich and who is poor. I have a better time looking at living expensive and food prices, but even that is a poor method to predict how much wealth someone has. I would thus not describe taxes as having a significant effect on wealth, and that wealth per adult is the result of a complex system.
I think you may mean (and if this is the case I generally agree) that when hormones trigger behaviors such as road rage, those behaviors have already been learned. Likewise, testosterone is unlikely to cause someone to shoot another driver because significant inhibitions against that behavior have been learned.
But hormones have an effect even in early childhood and before birth, when no behaviors have been learned yet. Prenatal hormones affect brain structure, and studies have found a link between hormones in children as young as 3 months and their choice of toys.[1]
Actually, chromosomes are a worse target for predicting behaviors in terms of sex-linked traits since genes during conception can and will be exchanged between the X and Y chromosomes in humans. This is why sometimes the SRY gene is found in women (XX) despite clearly having an operative uterus and ovaries. Nature loves to pick on us humans when it comes to assuming fixed traits.
I picked chromosomes and genes mostly because they are at least involved in the creation of the human brain, which was a bit hastily written. I agree that it makes for a poor prediction to determine who is going to have a tendency for mood swings.
Gender, to the degree that gender is not about culture, is quite far down the list of predictors, and even further down on the list would be hormones.
The literature I've read says hormones are "involved in the creation of the brain".
"Steroid hormones are a dominant and pervasive source of sex differences by mediating developmental processes that are enduring and establish adult physiological and behavioural responses relevant to the reproductive constraints of each sex."
From Multifaceted origins of sex differences in the brain, 1 February 2016, an open access article.
"Animal models have also allowed us to move beyond hormones and to an appreciation of the important role of sex chromosomes. Study of these mice has revealed important roles for chromosome complement on body weight and feeding, aggression and habit formation, to name a few."
And section 8:
"Some argue it is pure folly to study neuroanatomical sex differences with the hope of understanding sex differences in behaviour as the connection between anatomy and behaviour is often weak or even non-existent [50]. Indeed, the most celebrated sex difference in the brain, the SDN, has not been clearly tied to any specific behavioural or physiological endpoint, although see above discussion regarding sexual orientation. While it is true that anatomical or physiological differences in the brain often do not map onto clear differences in behaviour, does this mean they are not important or even, not real? Many studies of sex differences in brain anatomy or neural functioning are perfectly sound, meaning they are fully powered and technically executed using well vetted and accepted approaches, yet a strong correlation between variance in anatomy and variance in behaviour is about the best one can hope for in establishing a causal relationship."
I never said that hormones were the only influence, in fact I agree that genetics is also important.
Regarding behavior, and specifically the SDN, consider, for example:
The volume of a sexually dimorphic nucleus in the ovine medial preoptic area/anterior hypothalamus varies with sexual partner preference. Endocrinology. 2004
"In addition to a sex difference, we found that the volume of the oSDN was two times greater in female-oriented rams than in male-oriented rams."
Wired on steroids: sexual differentiation of the brain and its role in the expression of sexual partner preferences. Front Endocrinol (Lausanne). 2011
"Development of female-directed partner preference in the male is dependent on exposure of the developing brain to gonadal steroids synthesized during critical periods of sexual differentiation of the central nervous system"
The development of male-oriented behavior in rams. Front Neuroendocrinol. 2011
"Although our understanding of the biological determinants and underlying neural substrates of sexual attraction and mate selection are far from complete, compelling evidence is discussed that supports the idea that neural substrates regulating sexual partner preferences are organized during prenatal development"
I've been reading up on an embryologist that has been digging into the question of what defines sex in humans. She's concluding sex can be as varied as eye color and the like. So, sex isn't much a static category but rather a clustering of characteristics. It's something that may seem counter intuitive, but Nature doesn't have to obey our intentions.
How interesting. So using a statistically significant population sample, there will be no phenotypic differences between carriers of X versus Y chromosomes?
If so, science has progressed quite far in the last few years that I've been away.
There won't be much difference beyond reproductive roles and other physical traits, but the brain doesn't seem to be affected all that much, no.
Basically, there's no gene for being a programmer just as there's no gene for being a (good/bad) parent. Why would Nature bother to pre-compute/compile all possible states/outcomes? Better to compute/compile the essentials for a living species then let the rest be handled by history.
Evolution stops specializing when said specialization offers no beneficial adaptation sufficient for the metabolic cost. It's why the vast majority of living organisms have much simpler brains, body plans, and even reproductive strategies. Humans and other similar animals are rare little things in the vast ocean of simpler, more elegant mutations.
