#59. Neuromodulators as Peril Specialists [neuroscience, evolution]

NE   EV

Red: theory; black, fact

Solanum dulcamara, a plant with anticholinesterase activity.

“Life is difficulty.” -The Buddha Gautama

My PhD thesis was about a neuromodulator (acetylcholine) acting on mammalian brain. It was tough to decapitate so many rats; I never got used to it.

The basic theory

I conjecture that the primordial function of any type of transmitter substance acting on the g-protein-coupled cell-surface receptors or nuclear receptors of neurons was to coordinate the whole-organism response to some class of perils.

Table 1.

Peril	Substance	Failure mode
Extremes of heat and cold	glutamate and GABA	?
Predator	serotonin	depression
Parasite	histamine	phobia
Rival conspecific	noradrenaline	paranoia
Social isolation

#49. A Naturalistic Theory of Worship [evolutionary psychology, population]

 PO    EP

Red, theory; black, fact

Anytown, Canada, Apr. 11

Religion has a theory part and an applied part. The latter are the modes of worship. Since our moral codes are held by at least the Abrahamic religions to be commands from God, it would follow that it’s pretty important to conform to them, and most of us have difficulty doing this all the time. To help us, religion has developed a behavior-modification role, the role of the modes of worship.

The behavior-mod role aims at mitigating the human form of the Calhoun Effect—a tendency to aggression linked to rising population density but not to actual want per se. See post #36. Population density would have been an issue even millennia in the past when the world population was a minuscule fraction of what it is today, when people began living continuously inside walled cities for protection from their enemies. Within the inflexible confines of such a city, you have the makings of a human Calhoun experiment. Not coincidentally, the city of Jerusalem, sacred to three world religions, was a walled city. Nowadays, at a world population of 7.5 billion, it can be said that the world is our walled city. What can religion now tell us about how to get along?

Jerusalem in 1972

I’ll focus on the Abrahamic religions: Judaism, Christianity, and Islam, which developed in that order, all in the Middle East, each of the last two acknowledging its debt to the previous. I suggest that these three religions form a series of progressively increasing effectiveness in mitigating the Calhoun Effect, by an accumulation of folkloric knowledge. Thus, to see how modes of worship work, the purpose of this post, we need only examine Islam, likely to represent the most efficient solution. Form generally follows function most transparently at highest efficiency.

The Human Calhoun Effect

The natural human population density plot over time has a saw-tooth form, with linear increases alternating with abrupt decreases that return population density to some repeatable reset value. The linear segments are created by a negative-feedback controller in the limbic system that controls rate-of-change of population density to a constant positive value, not absolute density. At this writing, the world is probably coming to the crest of one of these linear segments, which began in 1950. The sudden population-density decrease that ends the cycle may have two phases: a first that produces population-density decrease by emigration, and a second that produces population-density decrease by mass murder, if the first phase does not take the system all the way to the reset value. The first phase accomplishes the biological function of dispersal, which is generally important for long-term species survival. The second guarantees overall stability on a multi-cycle time scale and wards off Malthusian catastrophes.

Both phases demand formally altruistic acts from individuals, but not of the warm-and-fuzzy kind. The first phase uses an exchange of anger signals to lock non-altruists out of the process so that the behaviour is stable over evolutionary time. The second phase locks out the non-altruists using an asymmetric exchange of signals: contempt signals going one way and sadness signals going the other way. The second phase culminates in the mass murder of the sadness signalers by the contempt signalers and the appropriation of all the resources of the sadness signalers by the contempt signalers. The last step guarantees that the contempt signalers will appear entitled to those outside the cycle.

Islam

Islam is conveniently summarized for our purposes as The Five Pillars of Islam, which are explained in the Quran, namely:

1) The Creed. 

(“There is no God but Allah, and Muhammad is the messenger of Allah.”)

2) Prayer.

3) Charity. 

(Concealed almsgiving is preferred.)

4) Fasting.

5) Pilgrimage.

The Theory

The creed is “The Great Why in the Sky” that people need for the control of their most difficult emotions. Strong emotion can be overridden by reason if that is required by a learned worldview, the validity of which the person is willing to bet their life on. Here, I attempt to supply a worldview based on evolutionary psychology. The creed, or “theory part” of a religion, also gets the rational mind cooperating with the behaviour-modification program, which acts on the emotional self. 

Rational override based on some creed may begin the work of extirpating someone's anger or sadness cycle, but behaviour modification may be necessary to finish it and produce a lasting improvement in the person's circumstances. These cycles may have deep roots inaccessible to consciousness and capable of perpetuating self-defeating behaviors if not treated appropriately.

Prayer superficially is a deliberate wasting of time, which is not free in metabolic terms because the worshipper has a basal metabolic rate that must be supplied whether he/she works or not. Regular inactivity is surely a luxury of only those enjoying abundance. This is implicitly saying to the anger and sadness/contempt programs: “Food is still plentiful, so it’s not time to get nasty.” These cycles may be triggered by signs of high population density, not actual want, but they should still be sensitive to metabolic signals that speak to whether actual scarcity exists. High population density acquired its potent psychological effects, after all, because it usually predicted scarcity in the environment of evolutionary adaptedness. Alternatively, prayer may work like meditation to turn off the internal voice and the unnecessary stress it causes if unscripted.

Charity, on the receiving end, that is, is for contempt signalers, who, as you will recall, are extremely entitled in the final stage of their emotional program. Accepting charity–goods that you did not work for–tells the contempt program that it has achieved its mission and can therefore halt. So, it does. In Islam, almsgiving is said to be best done in secret, an effect of which will be to spare the pride of the recipient. This will be an issue with contemptuous types.

Fasting–going without the necessities of life–is for sadness signalers and it tells their emotional program that they have given or lost all their resources to the contempt signalers, and therefore their program has achieved its mission and can halt. So, it does. On the other hand, based on my own experience with fasting, the practice may work by increasing the faster's energy level post-fast, and an increased energy level can solve a multitude of problems.

Pilgrimage is where you tell the anger-cycle program with your feet that you have been driven out of your homeland forever and must resettle elsewhere. Therefore, the program has achieved its mission and can halt. So, it does. 

Thus, the task of much religious behavior-modification can be likened to persuading a devil to depart by showing him false evidence that he has accomplished his purpose in coming, knowing that he is myopic. However, prayer tells him that he doesn’t even have to come in the first place.

#45. The Goddesses of the Glacier [evolutionary psychology]

EP

Red: theory; black, fact

(Spirits are flying in bearing mukluks and a parka.)

This post is about long hair, and I will argue that humans evolved the trait to keep them warm during geologically recent continental glaciations. (The teleological phrasing is used for the sake of brevity.)

Can having long hair really confer such a benefit under cold conditions? The anecdotal evidence supporting this idea seems abundant. For example, go to the site shown below

for a near-unanimous list of affirmative replies to the question: ‘Does long hair keep you warm?’ One respondent (#32), from Sweden, seems to have exactly reproduced the method for ensuring this that must have been used in eras of glaciation, assuming that our distant forbears could at least make themselves simple parkas out of animal skins.

They would have supplemented this protection by tucking their long hair down inside the parka. Leaving it outside would have been good fashion but bad engineering, since the locks would have been quickly parted by the first gust of wind and precious, life-saving body heat lost.

I began this with mention of goddesses, but of course the males would have had long hair too, probably a meter long, in outrageous violation of mid century cultural mainstream gender expectations concerning hair length.

I find that this situation suddenly makes better aesthetic sense if you imagine this long hair as tousled in the males and smooth and perfect-looking in the females and perhaps only in the portion showing above the neckline. Seen this way, both males and females look gorgeous in the imagination and the aesthetic problem is solved. I call this the "rock-star solution." The females could have smoothed their hair by lubricating it with oil and brushing, and a brush is not hard to make. Meanwhile, the males would only need their fingers for cultivating a charming, insouciant look.

While moderns socially code gender as hair length, this parameter was unavailable to our glaciation-era forebears because they would have been unwilling to cut their hair, knowing at some level of insight that they needed it for survival and mating success. Therefore, they might have coded gender as hair smoothness as described above. 

While writing this, I was struck by the amount of detailed information I was able to retrieve from my own aesthetic preferences, some of which would have evolved under stringent, cold-climate conditions to produce mate choices favoring traits with survival value. 

The heart may have its reasons that reason knoweth not, but reason is learning*.

PS: I have not mentioned beards yet and the main question there is why women do not have them. The answer seems to be that a long beard would interfere with breastfeeding, whereas long scalp hair can be pushed back. Moreover, women have more subcutaneous fat than men, so their thermoregulation problem in a cold climate would not be as severe.

*Based on a famous saying by the philosopher Blaise Pascal.

#43. Sunshine in Covey's Gap [evolutionary psychology, neuroscience]

EP   NE

Red, theory; black, fact

It is difficult to make a disagreeable emotion go away before one weakens and act it out, to their detriment. Techniques of true emotional control, i.e., making the bad feelings disappear rather than white-knuckle, open-ended resistance to acting them out, are not impossible, just non obvious. You just have to persuade yourself that this bad is good and believe it.

For the modern person, that second part, the believing, is difficult to achieve robustly if one is using religious solutions to the problem, the domain of soteriology (being "saved"), easier with psychoanalytical solutions, and easiest of all with scientific solutions. "Believing," here means being prepared to bet your life on the truth of a proposition.

Steven Covey writes in "The Seven Habits of Highly Effective People" that between stimulus and [emotional] response, humans have a gap in the causal chain and animals do not. In the gap are  imagination, self-awareness, conscience, and self will. George Santayana seems to have grasped this truth when he wrote: "Our dignity is not in what we do but in what we understand. The whole world is doing things." [source, Wiki quotes, accessed 11-06-2018]

Neuroscientist Joseph LeDoux has elucidated what could be the neural pathways that make Covey's gap possible. A direct pathway from the thalamus to the amygdala mediates the basic fear response, but an indirect pathway that leads from the thalamus up to the cerebral cortex and then down to the amygdala provides a more nuanced, intelligent amendment to the first response. Full cancellation of the direct pathway by the indirect would account for Covey's gap, and this could be done by a cortical relay through the inhibitory interstitial neurons of the amygdala that terminate on the amygdalar projection cells.

The doctrines of classical religion probably lead to such cancellation of emotions such as hate and fear by activating the same circuits that are used by a parent to reassure a needlessly fearful infant.

Apparently, classical religion is about getting people to do the right things for the wrong reasons. When the discipline of evolutionary psychology is sufficiently developed, we can look forward to the age when people do the right things for the right reasons.

#41. Corporate Sin [evolutionary psychology]

EP

Red, theory; black, fact

Not all of humanly willed destruction is due to two persons interacting, either in a sadness cycle or an anger cycle. Wars of depopulation and wars of dispersal represent these interactions promoted to the level of entire societies. This promotion theory assumes that the same hard-wired wetware is being used for both levels, but with the addition of a few more bits of code to support the social level.

Theologians such as Bishop Baycroft, writing in "The Anglican Way," are well aware of this extra dimension of human misery, referring to it as "corporate sin," and admit that it is a more difficult problem than individual sin. The advice I give in "Signaletics for Salvation" will not help you efficiently if your unhappiness has its roots in corporate sin (for example, if you are caught up in a military draft or are a slave), but it may be better than nothing. What about those extra bits of code?

The basic code design seems to be to transform a tiff between two individuals into a tiff between two leaders, then copy the emotions of the leaders into the heads of all the followers on both sides. Thus, a political leader is a kind of emotional conductor. This is why we have leaders.

By this theory, World War II was a tiff between Adolf Hitler and Winston Churchill, both famous for their speeches in which they inspired passions in their followers.

How do you get to be leader? The simplest answer seems to be that you just get famous and you are also someone who doesn't see a way to end his pain without involving the whole world. 

An attractive theory about fame, in turn, is that fame is 90% being-famous-for-being-famous, and 10% is being famous for something else, the predisposing factor. Human intergroup interactions have the form we observe because these predisposing factors are not random but are due to natural selection. Moreover, they are conditional upon prevailing conditions, such as the price of bread relative to wages. Finally, they already exist at the individual level. The process of garnering the absurd 90% of fame is the by-now familiar phenomenon of going viral, and its earlier historical equivalents. 

I imagine that this process is a positive feedback loop in the brain that involves the attentional system and Hebbian plasticity, the latter well known for having a built-in positive feedback. We also know that emotions are contagious (See: Hatfield E, Cacioppo JT, Rapson RL. Emotional Contagion. New York: Cambridge University Press, 1994).

#37. The Fallacy of Justice [evolutionary psychology]

EP

Red, theory; black, fact

The Biology of Badness

Evil and criminality may sub-serve either dispersal or preemptive population reduction, both valuable biological processes that tend to prolong the survival of species. 

The algorithms for achieving these ends would have been created over time by some form of evolution.

Evolution and the Role of Emotion

The genetically inherited parts of our behavior enter consciousness as emotions, and can therefore be easily identified. The main outlines of civilization are probably due to the inherited behavior component, and not to the reasoning, conscious mind, which is often just a detail-handler. How could civilization rest on a process that can't even remember what happened last weekend?

Thus, humans have a dual input to behavior, emotion and reason. The above arguments show that evil and criminality come from the emotional input. Yet the entire deterrence theory of justice assumes the opposite, by giving the person a logical choice: "You do this, we do that, and you won't like it. So you don't do this, right?"

However, I think that people commit crimes for emotional reasons. As usual, the criminal's reasoning faculties are just an after-the-decision detail handler. The direction that this detail handler then takes is fascinatingly monstrous, but this does not mean that crime begins in reason.

Conclusion: the deterrence theory of justice is based on a category error.

Past and Future Responses to Badness

Religion, with its emphasis on emotion, was all the formal "law enforcement system" anyone needed up until only about 200 years ago, at the industrial revolution. We may be able to go beyond where religion takes us by means of a disease model of criminality.

It does make some sense to lock criminals up, because with less freedom they cannot physically commit as many crimes. Many prisons become dungeons, however, because of the public's desire for revenge. However, all revenge-seeking belongs to the dispersal/depopulation dynamic and is thus part of the problem. A desire for revenge may follow a crime very predictably, but logically, it is a non-sequitur.

A more nuanced theory of crime prevention is possible, where logical and technological constraints on behavior complement efforts to reduce the motivation for committing crimes at the source: the individual's perception of the fairness of society, which will be due to a combination of objective realities and the filters through which they are viewed. However, I originally wrote as I did because I don't think that logical and technological constraints are the squeaky wheel at the moment.

#35. The Thought Process Through the Ages [evolutionary psychology]

EP

Red, theory; black, fact

In the beginning, there was theology. At some point, intellectual endeavor split into wrestling with reality questions vs. morality questions. Then people had to figure out when to go with your gut and when not to.

_________________

Thought sources	Inputs	Output insights
		Reality (What is)	Blend	Morality (Thus…)
PGSd+senses	Emotion	politicsc		religionc
	Blend	astrologyb ↕	← theologya →	Jewish lawb ↕
Education+senses	Reason	sciencec		lawc

a. primordial condition

b. output distinction added

c. input distinction added

d. evolution; see post 22

If politics and science seem like strange bedfellows, consider that ancient rulers used to consult astrologers before making major decisions.

Just as emotion must not be allowed to contaminate scientific thought, is it equally true that reason must not be allowed to contaminate religious thought? Is failure to observe this restriction the cause of religious schisms?

#33. Emotions [evolutionary psychology, genetics, neuroscience]

EP   NE   GE

Red, theory; black, fact

A Genetics Theory 

All sexually reproducing species may have a long-range guidance system that that could be called proxy natural selection, or preferably, post-zygotic gamete selection (PGS). This is basically a fast form of evolution in which particular body cells, the gametes, are the units of selection, not individuals. Selection is conjectured to happen post-zygotically (i.e., sometime after the beginning of development, or even in adulthood) but is retroactive to the egg and sperm that came together to create the individual. 

Each gamete is potentially unique because of the crossing-over genetic rearrangements that happen during its maturation. This theory explains the biological purpose of this further layer of uniqueness beyond that due to the sexual mixing of chromosomes, which would otherwise appear to be redundant.

Emotions Represent Fitness 

Our emotions are conjectured to be programmed by species-replacement group selection and to serve as proxies for increases and decreases in the fitness of our entire species.

The Corresponding Mechanistic Theory 

A further correlate of an emotion beyond the cognitive and autonomic-nervous-system components would be the neurohumoral component, expressed as chemical releasing and inhibiting factors that enter the general circulation via the portal vessels of the hypothalamus, blood vessels which are conventionally described as affecting only the anterior pituitary gland. These factors may reach the stem-like cells that mature into egg and sperm, where they set reversible epigenetic controls on the level of crossing-over that will occur during differentiation. 

Large amounts of crossing-over are viewed as retroactively penalizing the gametes leading to the individual by obfuscating or overwriting with noise specifically the genetic uniqueness of said original gametes. In contrast, low levels of further crossing-over reward the original gametes with high penetrance into the next generation. 

Here we have all the essential ingredients of classical natural selection, and all the potential, in a process that solves problems on an historical timescale.

The Limited Scope of Crossing-over

Crossing-over happens only between homologous chromosomes, which are the paternal and maternal copies of the same chromosome. Human cells have 46 chromosomes because they have 23 pairs of homologous chromosomes. 

The homologous-chromosome-specificity of crossing-over suggests that the grand optimization problem that is human evolution has been broken down into 23 smaller sub-problems for the needs of the PGS process, each of which can be solved independently, without interactions with any of the other 22, and which involves a 23-fold reduction in the number of variables that must be simultaneously optimized. 

In computing, this problem-fragmentation strategy greatly increases the speed of optimization. I conjecture that it is one of the features that makes PGS faster than classical natural selection.

Do Chromosome-specific Signaling Pathways Exist?

However, we now need 23 independent neurohumoral factors descending in the bloodstream from brain to testis or (fetal) ovary, each capable of setting the crossing-over propensity of one specific pair of homologous chromosomes. Each one will require its own specific receptor on the surface of the target oogonia or spermatogonia. In the literature, I already find a strange diversity of cell-surface receptors on the spermatogonia. I predict that the number of such receptors known to science will increase to at least 23. None of this is Lamarkism, because nervous-system control would be over the standard deviation of traits, not their averages.

Naively, this theory also appears to require 23 second messengers to transfer the signals from cell surface to nucleus, which sounds excessive. Perhaps the second messengers form a combinatorial code, which would reduce the number required by humans to log₂ (23) = 4.52, or 5 in round numbers. This is much better. Five second-messenger systems are known, these being based on: cyclic AMP, inositol triphosphate, cyclic GMP, arachidonic acid, and small GTPases (e.g., ras). The AND-element that would be required for decoding could be implemented straightforwardly as a linear sequence of transcription-factor binding sites along the DNA strand. However, many mammalian species have many more than the 32 chromosome pairs needed to saturate a 5-bit address space. If we expand the above list of second messengers with the addition of the calcium/calmodulin complex, the address space expands to 64 pairs of homologous chromosomes, for a total ploidy of 128. This seems sufficient to accommodate all the mammals. Thus, a combinatorial second-messenger code representable as a five- or six-bit binary integer in most organisms would control the deposition of the epigenetic marks controlling crossing-over propensity.

It Gets Bigger

If the above code works for transcription as well as epigenetic modification, then applying whatever stimuli it takes to produce a definite combinatorial second-messenger state inside the cell will activate one specific chromosome for transcription, so that the progeny of the affected cell will develop into whatever that chromosome specifies, be it an organ, a system, or something else. And there you may have the long-sought key to programming stem cells. You're welcome.

The requirement that the evolution of each chromosome contribute independently to the total increase in fitness suggests that a chromosome specifies a system, like the nervous system or the digestive system. We seem to have only 11 systems, not 23, but more may be defined in the future.

Illustration credit: By Edmund Beecher Wilson - Figure 2 of: Wilson, Edmund B. (1900) The cell in Development and Inheritance (2nd ed.), Category:New York: The Macmillan Company, Public Domain, https://commons.wikimedia.org/w/index.php?curid=3155599

#27. The Origin of Consciousness [neuroscience]

NE

Red, theory; black, fact

We begin life conscious only of our own emotions. Then the process of classical conditioning, first studied in animals, brings more and more of our environment into the circle of our consciousness, causing the contents of consciousness to become enriched in spatial and temporal detail. Thus, you are now able to be conscious of these words of mine on the screen. However, each stroke of each letter of each word of mine that now reaches your consciousness does so because, subjectively, it is "made of" pure emotion, and that emotion is yours.

Some analogies come to mind. Emotion as the molten tin that the typesetter pours into the mold, the casting process being classical conditioning and the copy the environmental data reported by our sense organs. Emotion as the area on one side of a fractal line and sensory data the area on the other side. Emotion as an intricately ramifying tree-like structure by which sensory details can send excitation down to the hypothalamus at the root and thus enter consciousness.

The status of "in consciousness" can in principle affect the cerebral cortex via the projections to cortex from the histaminergic tuberomamillary nucleus of the hypothalamus. Histamine is known to have an alerting effect on cortex, but to call it "alerting" may be to grossly undersell its significance. It may carry a consolidation signal  for declarative, episodic, and flash memory. Not for a second do I suppose all of that to be packed into the hippocampus, rather than being located in the only logical place for it: the vast expanse of the human cerebral cortex.

#26. Why Organized Religion? Theory Two [evolutionary psychology]

EP

Red, theory; black, fact

Emotions are an "endophenotype," a term from functional magnetic resonance imaging, that provides a useful stepping stone from evolutionary arguments to explanations of our daily lives. 

Starting with the Emotion 

What is the mood or feel as you enter a place of worship and participate in the ceremonies conducted there? More than anything else, the mood is one of great reverence, as though one is in the presence of the world's most powerful king. Kings are supposed to "represent their race." 

Problem

If the emotional outline of people's behaviour is being partly randomized in each generation by recombination-type mutations, a consistent moral code seems impossible if we assume that morality comes mostly from peoples' inborn patterns of emotional reactivity, that is, the sum total of everyone's preferences. The purpose of a king may be to find and coincide with societies' moral center of gravity, around which a formal, if temporary, moral code can be constructed. In a complex society, everyone must be "on the same page" for efficient interaction. 

It Gets Bigger

The same problem no doubt recurs each time organisms come together to form a colony, or super-organism: the conflict between the need of a colony for coordination of colonists and the need of evolution for random variability. Such variability will inevitably affect the formulation and interpretation of the coordinating messages that the colonists exchange, like all their other inborn characteristics. 

A Social Solution 

With kingship comes the corrupting influence of personal power and  tyrannical government. Replacing a real king with a pretend-king named "God" would seem to be the solution that accounts for organized religion, but then one loses the flexibility that goes with having a flesh-and-blood king who can change his predecessor's laws based on current popular sentiment.

Mechanistic Interpretation 

However, human nature may well have a core-and-shell structure, with an "unchanging" core surrounded by a slowly changing shell. The former would be the species-specific objective function and produced by species-replacement group selection within the genus, and the latter would be due to selection of smaller units, and would represent the stratagems hit upon by our ancestors to meet the demands of the objective function in our time and place. This shell part may account for cultural differences between countries. The core may be implemented in the hypothalamus of the brain, whereas the shell may be implemented in the limbic system. The core, being very slow to change, could be managed by organized religion, whereas the shell could be codified by the more flexible institution of government. Though the core is unchanging overall, specific individuals will harbor variations in it due to point mutations, necessitating the standardizing role of religion. Synaptic plasticity would then be used to cancel the point-mutational variation in the objective function.

The Big Picture 

The core may consist of four pillars, or regulatory themes: regulation of genetic diversity, memetic diversity, altruism, and dispersal. Our energetic investment in obtaining each item is to be optimized.

#24. Proxy Natural Selection from the Inside [evolutionary psychology, genetics]

EP   GE

Red, theory; black, fact

Morning hymn at Sebastian Bachs' By Toby Edward Rosenthal

What Does Darwinian Fitness Feel Like?

My first post on post-zygotic gamete selection (PGS) left open some questions, such as what it should feel like, if anything, when one is fulfilling the species objective function and being deemed "proxy-fit" by one's own hypothalamus.

How Our Emotions Program Us

I conclude that it's just what you would think: you feel joy and/or serenity. Joy is one of Ekman's six basic universal human emotions, the others being fear, anger, disgust, sadness, and surprise. I think that emotions collectively are the operations of the highest-level human behavioral program. (That is, the program in its broadest outlines.) The unpleasant emotions force you to get off the couch until they are taken care of, and joy lets you get back on. Thus, the unpleasant four are the starting emotions, and joy is the stopping emotion. 

Surprise may be a meta-emotion that tells you that your threshold for experiencing one of the other emotions is too high, and immediately lowers it. Each activation of an emotion may tend to lower the threshold for activating it next time, which implies a positive feedback loop capable of changing the personality to suit suddenly changed circumstances, especially if the emotion eventually begins issuing with no trigger at all.

Where Our Emotions Come From

To relate this to the mechanism of PGS, the crossing-over events that went into making the sperm cell that made a given person would theoretically affect brain development more than anything else, specifically connecting some random stimulus to one of the unpleasant primary emotions. This creates temperament, and thus  personality, which is the unique quality which they have to offer the world, and on which they are being tested by history. If the actions to which their own, special preferences propel them are what the species objective function is looking for, they succeed, feel joy and serenity, and experience an altered methylation status of the DNA in the spermatogonia if male, which suppresses further crossing over in the manufacture of sperm, so that their personality type breeds true, which is what the population needs. Famous musical families, for example, may originate in this way.

PGS is quick evolution to respond to challenges that come and go on less than a multi-thousand generation timescale, and it explains the complexities of sexual reproduction.

A Flaw in the Argument, Addressed

However, trees have no behavior, much less personalities, and yet they have sexual reproduction. However, trees probably adapt quickly not by behavioral change, but by changes in their chemistry. The chemistry in question would be the synthesis of pesticidal mixtures located in the central vacuole of each plant cell. In terms of such mixtures, each tree should be slightly unique, an easily testable prediction.

The Big Picture 

Each of the four unpleasant "starting" emotions may sub-serve one of the four pillars of the species objective function. Thus: sadness, altruism; disgust, genetic diversity (due to point mutations; what is motivated here is the screening of such novelties during mate selection, screening always being the expensive part); fear, memetic diversity (or motivating prescreening of memetic novelties through fear of public speaking); anger, dispersal.

Each of these emotions seems to have another use, in preserving the life of the individual, as opposed to the entire species. Thus: sadness, unfavorable energy balance; disgust, steering one away from concentrations of harmful bacteria; fear, avoidance of injury and death; anger, driving away competitors for food and mates.

Picture credits: https://commons.wikimedia.org/wiki/Commons:Copyright_tags/Country-specific_tags#United_States_of_America