There is a mis-match between human psychology - which mostly evolved in a context of hunter-gatherer societies - and life in modern society: but the mis-match seems to be much more extreme in women than men.
Essentially, the mis-match is evident in terms of human choice and especially in relation to 'reproductive success'.
(Happiness is irrelevant to this - natural selection operates on reproduction, and happiness is merely a means to that end.)
Reproductive success of a person is, roughly, the relative proportion of viable offspring it contributes to the population - this is, roughly, measured by the number of children born to a person (minus those children who die before completing their reproductive lifespan).
In the modern world where death rates are very low, reproductive success can pretty much be measured as the fertility rate: the number of children.
If you look at figures 1 and 2 in this paper -
you can see that the situation is very different for men and women.
Men are biologically reasonably well adapted to modern society - but not women: the graphs go in opposite directions in this particular sample.
Overall, as men become wealthier and higher in status it either increases the number of children (which is what would be expected, biologically - and is the reason why men strive for status) - or at least does not damage reproductive success too much.
(Of course, in a sample worldwide, this would not hold, since less wealthy men would have a lot more children. This argument only applies to modern, developed societies with control of reproduction.)
But as women become more wealthy, more educated (and even more so with respect to increasing IQ) the number of children declines sharply and the proportion of women who are childless increases.
Why should women be so much more adversely affected - from a biological perspective, purely in terms of reproductive success, by modernity?
Because, almost certainly, in the past (in the pre-contraceptive era) increasing wealth among women almost certainly strongly increased reproductive success.
It is contraception which is the main factor.
Women seem predisposed to avoid or minimize childbearing, in proportion that they are more intelligent, educated, wealthy and high status.
This is surprising, and remarkable, and - currently - pretty much unexplained.
Here are some ideas.
In biology in general, females are (almost always) the investing sex: they invest a lot more resources into offspring (before and sometimes after birth) than males.
In order to allocate investment most female mammals will temporarily suppress reproduction under conditions of stress - fear of violence, starvation, disease etc.
This can be conceptualized in terms of saving resources for better times which may be ahead.
Reproductive suppression may be achieved by not ovulating, by reabsorbing the fetus, by abandoning or even killing newborn offspring etc.
Maybe women in modern society are engaged in reproductive suppression (mostly by means of contraception and abortion): maybe there is (at some level) a perception of 'stress'; maybe (in some way) the modern situation is perceived as alien and hostile to such an extent that reproduction is deferred (in hope of better times ahead) - but since this situation does not change, better times never arrive and reproduction gets (in practice) deferred permanently - until the reproductive lifespan is over.
Or could it simply be distraction? Any focus on reproduction is overwhelmed by the multiple attractions and distractions of modern evolutionary novelties.
In historical societies reproduction just happened as a by product of instinct: people sought 'happiness' and the children just came along (and there was no way of stopping them).
Now, with the presence of so many evolutionary novelties, people in general are confused and distracted, such that if they 'do what comes naturally' it does not lead to having children - but merely to (mostly short lived) pleasure/ avoidance of suffering.
In modern societies this means that women behave much more bizarrely (from a biological perspective) than men - from a biological perspective, women (by choice) make themselves ugly and unattractive (with fashion, by their behaviour), and (biologically) waste their time and resources.
But why should women be more 'confused' by evolutionary novelties than men?
Perhaps because women are more peer oriented than men.
Each man is, in a biological sense, a loner who seeks status, seeks to become the dominant male and get the lion's share of reproduction. Each man is against other men - except that self-interest dictates that one way to pursue self interest is via alliances.
But in historic societies, alliances were very difficult to sustain unless underpinned by genetic relatedness: most gangs and tribes were of male relatives.
Otherwise male v male competition would tend to break them up.
But women seem more able and motivated to form alliances with unrelated women (perhaps because a women would usually move to the husband's tribe, and needed to establish herself among female strangers?). Therefore, whatever the reason for greater peer orientation, women are strongly influenced by the opinions of other women (or, more exactly, by what they perceive to be the opinions of other women.
So women will do almost anything which they perceive to be necessary to fit with what they perceive to be the peer group of other women - from the mild level of sending innumerable greetings cards, through adopting fashions which (nearly always) usually make them less attractive; up through drunkenness and promiscuity, to tattooing, foot-binding and other self-mutilations.
(By less attractive I mean objectively so, from a biological perspective such as the massive amount of data on male sexual preferences cross-culturally and the correlations between attractiveness and signals of reproductive potential and what makes a potentially good long term partner and parent.)
All of these originated and enforced by that biggest and most influential of evolutionary novelties: the mass media, which in this instance functions as a super-stimulus interpreted as representing the female peer group.
So, a couple of ideas ...
1. that the very high level of maternal investment in humans makes women relatively highly likely to engage in reproductive suppression under situations of stress: and modern society is perceived as extremely stressful - so reproduction is deferred, indefinitely...;
2. that because women are more peer orientated, they are more vulnerable to influence by the mass media - which is an evolutionary novelty functioning as a superstimulus that is perceived to represent the female peer group...
but the phenomenon seems undeniable and calls out for explanation.
To restate the question:
Why are women so much more adversely affected (in a biological sense: reproductive success) by modernity than are men?
Or, why do modern women choose - on average - to damage their reproductive success?
Or, why does the pursuit of happiness – under modern conditions – cause de facto reproductive suppression in women so much more strongly than in men?