Text for A Cuckoo's Egg in Darwin's Nest?: Active Genotype-Environment Correlation (Revised!)

(1st posted 6/14/01, minor revisions at this time and reposted)

There are 2 threads: (1) a plea that we recognize the "active" aspects of organisms, that we are not passive casts and (2) a redefinition of "nonshared" environment. Look for a separated posting soon on "Cleaving Nonshared Environment."
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Differences between EP & BG

Behavior geneticists (BG) seek to define trait differences that are systematically related to gene differences. Within evolutionary theory, evolutionary psychologists (EP) seek to define the universals of behaviors that are characteristic of humans. To one, understanding variance is an idee fixe, to the other that same variance can be an annoyance, an outcome of pathogens or scientific error (Bailey, 1998). Not only are goals different between BG and EP but so are their emergent methods, models, equipment, list serves, texts, journals, and stories about human nature.
This paper argues, by caricature, that there is an additional fundamental difference between EP and BG that goes to the core of what we believe about ourselves. In EP's mirror, we are the result of 4 billion year's of reentrant casting by heat, drought, cold, and monsoons. BG protests that we are opportunists and hustlers, changing our gambits in relative instants, migrating and rampaging to enforce our preferences wherever we go. Finally, between the two orders sketched in EP and BG there is a phase transition (Kauffman, 1995; Brody, 1999; Sole & Goodwin, 2000) that is described by AGErxy. We occupy that phase and shape environments to our needs but must husband our niches so that they won't kill us. Our "hopes and fears through all the years" lie within that phase transition.

Sketch #1: Pygmalion
Selection (variation, polling, and amplification, Sporns, 1994) produced traits through a systematic change in gene frequencies across generations. Selection further crafted a net of psychological adaptations that consist of physical and psychological algorithms that manage survival tasks. Through selection, we have an evolved architecture of modules that guide us to find ripe berries and gossip, avoid dirty water and old dead animals, and separate our meandering wife from her lover or hand her to him with our blessings provided that he feeds her and doesn't beat our children.

In evolution's mirror, we see the places that we've been:

1. Environment is a mold, genes are a hypothetical construct within EP, cast by environment into their present arrangements.

2. Equal environments produce equal outcomes. For our social modules, an "environment of evolutionary adaptation" (EEA) existed in Africa and made all peoples alike.

3. The Mismatch Lament: when environment is not stable, genes lag behind. Thus, we're miserable because we left where we were and our genes are slow learners (e.g., Nesse & Williams, 1995).

4. EP is generally historical: we can't manipulate gene frequencies except in bacteria, shorter lived species, and in computer simulations. In regard to human behavior, we amass correlations and competing stories.

Sketch #2: Galatea
"All things living are in search of a better world." Popper, 1989, p. vii.

In EP, we see that we've been where none of us wants to return; through BG we glimpse the places that we want to build. Consistent with Popper's vision, we might amend EP's story and savor both "active Darwinism" (Popper, 1989, p. viii) and the tradition of Leibnitz (cited in Allport, 1955), Galton (1883), Darlington (1953, cited in Plomin, 1994), Allport (1955), Plomin et al. (1977), Scarr and McCartney (1986), Cohen (1999), Plomin et al., (2000), Coen (2000), Turner (2000), and Lewontin (1998/2000).

Active genotype-environment correlation
Genes and environments are not independent events, similar genes help their carriers to construct similar worlds for genetic advantage. Masses of observations about creatures who build hives and nests are consistent with this principle (Von Frisch, 1974; Dawkins, 1982; Hansell, 2000, 1984; Turner, 2000). And parents, whether ducks or psychologists, will tend to share their material and conceptual worlds most with offspring who have similar genes (Darlington, 1953, Scarr & McCartney, 1983; Plomin et al, 1977; Plomin et al, 2000). One outcome is that traditional psychological measures of human environments have a genetic loading (Rowe, 1994; Plomin et al, 2000). That is, there is a genetic cast even to the environment that is composed from the content of our memories.

1. Whether in studies of identical twins reared apart (Bouchard, et al., 1990) and in studies of drosophila (Weiner, 1999), BG points to highly detailed outcomes from genetic similarities. Thus, AGErxy is more than "obscure interactionism" (Lewontin, 1998/2000). Within the range of environments that are of greatest interest to us, genes and their epistatic combinations (Haig, 1997) appear to be the flight plan and guidance system.

Identical twins, however, can sometimes be different from one another because of the stress of their having shared a womb (Segal, 1999). Because most of us didn't share a womb, most of us is more an identical twin of his or her nature than is evident from what we see in identical twins. Thus, we can't hang our idiosyncrasies from environmental pegs.

Galatea creates her own form and takes her first breath.

2. Genes create order, often through receptors that might or might not match a particular item in the physical setting; physical settings do not become environments until genes organize them (Lewontin, 1998/2000). (Likewise, environments do not become sciences until Ed Wilson organizes them. See Wright, 1988, p.138 in regard to Wilson's comment that he has always liked turning messy subjects into orderly ones.) Like any organism, we select consequences in our worlds and repeat whatever activity produced them. Genes sculpt, within the limits of developmental noise (Darlington, 1957; Maynard Smith, 1998; Lewontin, 1998/2000) motor and sensory tools that take advantage of any possible opportunity to improve on their surroundings.

For example, microenvironments are more common than we appreciate, whether in plants, coral, lugworms, and crickets (Turner, 2000) or in the dyads of mothers and sons. We can also expect the competition between different species of plants to have outcomes that owe much to reciprocal strategies that benefit both competitors (Margulis, 1998). Red Queen effects can be expected not only between competitors but also between an organism and its environments (Van Valen, 1973, cited in Lewontin, 1998/2000, p. 58)

3. Genetic variables lead to a continuity of strategies and a continuity of personal experience even though such strategies have varied outcomes in different settings. Environment's effects are often inconsistent, transient, or reversible. Thus, shared environment (SE) from parents erodes as children mature, very likely so does the SE from peers as an individual moves into new groups.

Furthermore, environment can sometimes switch genes on or off (genotype-environment interaction, Plomin, et al, 2000) so that we are depressed at home but happy at work. A delusion that we are fatally ill can dominate our mental stage at work but vanish when we play miniature golf with our fiancee. Failure in one setting has effects that may be reversed by a later success or even a concurrent success in a different realm. Reactions to early trauma and early success emerge as a joint function of both the events and of our sensitivity to those events.

Most irreversible effects will arise more from maturational changes in the individual and less from instruction. A young defiant male will still be defiant if somewhat castrated by time when 20 years older; glowing coals of anger will be expressed against his 3rd wife but he no longer fuels the torch that he once aimed at his tearful mother. Some lessons will be permanent because of evolved, genetic, systems within the student for one trial learning of some experiences. And some permanent lessons may be permanent because the student with time is no longer receptive to change.

4. Genes lead to receptors and evolution will follow them, sometimes having novel effects not easily predicted by natural selection. For example zebra finches can prefer mate characteristics --- colors of leg bands and decorative head crests --- that do not ordinarily exist (Burley, 1998). Burley and her team concluded that novel attractive traits may have high potential to evolve through latent receptor preferences.

5. Genetic continuity across phyla hints that our most persistent mental joys and complaints may predate the Pleistocene (cleverly dubbed the "plasticene" in a novel by Andrews, 2001). For example, we share DNA with flies and produce an apparently normal fly rather than a gifted one. Further, many of our contemporary automatic reactions to height, blood, rasp growls, poisons, sickness, and social contests may be recursive products from the times that we spent as smaller and possibly hairless creatures (MacLean, 1991; Brody, in press).

6. Genes are rarely equal and may NEVER be equal except in human definitions. Even MZT will someday be found to have genetic differences between them; we only have to look closely enough. Genes manipulate environment to extend the range of conditions for genetic operations (Dawkins, 1982; Turner, 2000). These adjustments fine tune environments for a better match to genetic idiosyncrasies and attenuate both developmental noise and chaotic outcomes from environmental variation.

Galatea puts on her lip gloss

The irrelevance of Darwinian shamanism

Most of us are sufficiently intact to manage our own "mismatch"; we are most likely to need help in the areas where we are deviant rather than average. When we need a doctor, we benefit less from tales about human similarities and more from a detailed map of the quirks that identify our parents, grandparents, and children.

"Good enough" environments are not good enough
The differences between most instructors are largely irrelevant within the context of a "good enough" environment (Scarr, 1992; Rowe, 1994). If evolution were only "chance on the wing" then none of us would have survived millennia of wars, droughts, and famines. Our resilience suggests that genes get their way in a wide range of physical and social environments. In spite of genetic specificity and variation, "good enough" parents, teachers, employers, and healers usually satisfy students' and clients' demands because students and clients modify their own quirks, picking from whatever instruction is offered. (Chiropractors and GPs treat more depression than psychiatrists; naturopaths give traditional medicine a stiff run for customer loyalty and satisfaction. Educators agree with a "good enough" premise about themselves when they swap children every fall.)

However, it's likely that "good enough" environments do not remain "good enough"; we personally try make them better. Even cloned "good enough" teachers, such as computer terminals, do not remain clones: students load software and slogans that were not originally part of the computer. Popular machines are defined by options as much as by processor speed; we value them because they give us personal choices.

On the other hand, Harris (1995) and Scarr (1992) are wrong when they suggest that parents can be swapped randomly without exerting a cost on children. Effective parents use their family history to help their children discover and appreciate their own traits and the conditions under which those features are productive (Galton, 1883; Brody, 1998). Swapping parents would reset everyone to the same level of ignorance that now occurs for adoptees.

Prenatal Environments

Galton (1883, p. 131) observed, "Nurture acts before birth, during every stage of embryonic and pre-embryonic existence, causing the potential faculties at the time of birth to be in some degree the effect of nurture." By definition, different prenatal environments give siblings different NSEs and have been mentioned as causes for differences in aggression, emotional variation, gender, and minor physical anomalies (Cohen, 1999). Prenatal NSE might also be a product of: genomic conflicts that are waged for the course of the child's life (Haig, 1993; Li et al, 1999; Haig, 1999), stress in the mother's life, the number of children that she already carried, and her use of alcohol and nicotine (Cohen, 1999).

There is, however, a substantial range of variability associated with each of these factors. Thus, even here, the balance of fetal vulnerability vs. fetal assertion is indeterminate.

Emergenesis?
Grandparents, parents and children lead highly similar lives (Galton, 1883); so do identical twins. Lykken conceived of "emergenesis" to account for the signature quirks in MZT reared apart and for talents in math or music that appear in one generation but do not appear in prior or succeeding generations (Lykken, 1982; Lykken et al., 1992). In this latter instance, it may be that a closer inspection, especially of maternal genetic contributions would show more continuity than is described by Lykken and others.

Within BG far less of individual variation is considered to be random; differences are orderly and significant between adjoining generations and adjoining families (Galton, 1883). Understanding that variation and looking for close similarities between the immediate generations of a family offer great clinical and educational promise. In my own case, I became a psychologist (a replay of my father's talents) and a showman (a replay of my mother's) but catalyzed by a different education that helped me to do the things that they would have done. These similarities can be found in nearly any biography or mirror or behind any door.

Diverse interactive nets of weak influences exert force at a distance
Genes are local organizers that appear to be essential in diverse "interactive nets of weak influences" (Lewontin, 1998/2000) between components such as seen within genomes, organs, organisms, or ecosystems (Wilson, 1975; Kauffman, 1995, Lewontin 1998/2000). The emergent cooperative nets between humans extend our personal genetic preferences, reforming earth (Wilson, 1998; Wright, 2000; Bloom, 2000).
Collectivism always emerges in congregates of similar organisms, cooperation produces stability when inter connectivity reaches defined thresholds (Kauffman, 1995; Wright, 2000; Bloom, 2000; Brody, 1999, in press). By one story, bacteria and professors emulate bees because bacteria share a gene with each other; so do professors and bees, respectively. A second story is that social environments instruct us to do good in spite of our instincts (Huxley, 1894/1995). According to a third story, one that does not send bees to church, human initiative is a shifting web of computations and the web stabilizes when there is sufficient cross talk between participants.

Even though each of us is different, social behavior --- a genetic product ---- holds us together and each of us compensates for flaws in our leaders, followers, and peers. (Some of us are not particularly social but benefit from the social leanings of the people around us!) While cultures may have similarities for child rearing, mating, aggression, hierarchies, and gathering food, it is neither true nor necessary that every individual within them have those traits in equal strength.

Because of human networks, we have become the selective factor for many species on earth: environments compete and are amplified according to human preferences. Genes in humans are functionally "genes for" environments (Wilson, 1998) and through humans, environmental features become heritable. The recursive effects from cooperative human genetic interests resemble a Sorcerer's Apprentice; "genes for" lawns will sometimes drive "genes for" fish into extinction.

Instructionism
Many who talk about the universal similarity of humans and the inequities of environment probably do so for personal status and to impose an order that fits their own nature (Krebs, 1999.) At the same time that we recite compliance with someone's rules and advocate those rules to other people, most of us evade the rules that we advocate. When imposing rules on other people, when trying to instruct them, we are generally endorsing rules that benefit us more and our audience less. Similarly, parents often make their children behave for the parents' interests and teachers who instruct are to be less trusted than teachers who help us to discover. Instruction thus leads to an imposed denial of competing self interests (Gintis, 2000).

"Why is 'me'?"
There are contrary whispers about freedom and environment: "Certainly one can view the environment as being just as constraining of free will as the genes. In the purely environmental perspective, there is no innate genetic drive demanding to be expressed. People are blank slates who are conditioned by environment to react in expectable ways" (Wright, L., 1997, p. 156). Brave New World was about environmental determinism (Ridley, 2000).
Nelkin (1999) discusses the popular lure of genetics explanations. A current example, Jessica Andrews, was taught about "learning" in school but she also sings, "I am Rosemary's granddaughter, spitting image of my father, and when the day is over, my mama's still my biggest fan ... It's all a part of me, that's who I am." Jessica is 16 years old and her song occupied the #1 spot recently on the country and western music charts. Her audience is usually blue-collar, conservative in religion and politics, and apt to be skeptical of evolution but they loved her song!

Jessica and her audiences understand BG and environment but without the equations; those same people squirm if you mention "adaptations." That difference in impact constitutes a problem for EP. Even with the topic of sexual selection (which really IS about having the same stuff but more of it or more quickly or in more intense colors), EP is not a lot of fun. It ignores our most intense, our most soulful variables, the ones that led Nat Angier and Meredith Small to proclaim, "I'm different" to their audiences in the New York Times. And mothers rear sons less to fit in and more to take care of themselves. But EP has no answer for "Why is 'ME'?" According to EP, there isn't an answer because there is no question. Your "me" is just like my "me," we all have the SAME me."

Behavior genetics allows the question and suggests an answer.

Lindon Eaves (in L. Wright, 1997, pp. 155-156) asserts:

"A philosopher who was talking about twins said that maybe it's freedom that makes identical twins different. Frankly, I don't believe that for a minute. It could be freedom that makes them alike."

"Quite clearly it's crass to equate genetics with determinism and environmentalism with freedom. I think human freedom means something about the capacity of the human organism not to be pushed around or dominated by external circumstances. .... Freedom is the ability to stand up and transcend the limitations of the environment."

"One way of looking at it is, if you're going to be pushed around, would you rather be pushed around by your environment, which is not you, or by your genes, which in some sense is who you are."

I knew a sparrow who understood Eaves. She fluttered on the ground near my barn, her right wing immobile. I put her inside a large glass tank with seeds, water, morning sunlight ---- a glass, cardboard, and sawdust nest in my family room where she ate and splashed when I wasn't in the room and where she hid beneath an inverted box at one end of the tank when I was. After several days I picked her up and she asserted her genetic self interests and free will, biting the soft skin between my thumb and index finger. I then asserted my genetic self interests by yelling "Ouch" and taking a picture of her biting me. After 10 days, she regained flight and chose not the food and security that I offered but an open door to choice, danger, and a season of making more sparrows. I, the environment, changed the bird, the bird changed me, and we changed each other.

Pygmalion perhaps loved and respected Galatea far more when she had a will of her own.

References
59 and propagating! Available on request.

Thanks and Contact
FOR HER FRIENDSHIP
"Sure thing I can do it." Dori LeCroy.
email: DoriLeCroy@aol.com.

FULL MANUSCRIPT AND REFERENCES
James Brody, Ph.D, 1262 West Bridge St., Spring City, PA 19475, USA.
Telephone: USA 610-948-5344
email: jbrody@compuserve.com.
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Appendix: Cleaving nonshared environment (NSE)

Truism: both G & E are essential; you won't get much without both of them. However, our current model bothers me. I probably don't understand it, but maybe it has a flaw. The following depends starts with some definitions from Plomin et al, 2000.
Phenotypic variance (outcomes) are the result of genetic variance and environmental variance.

Environmental variance comes in 2 forms: shared (SE) and nonshared (NSE). SE refers to those segments of environments that make people the same. SE is typically 0-1% except in a few exceptions such as studies of younger children.

NSE refers to those segments of environment that make people different. NSE often contributes 30-40% of phenotypic outcomes, an amount roughly equal to the phenotypic variance from genes. (Measurement error is also included in NSE.)

Oddly, there is no independent definition of SE or NSE: both are defined by the existence of similarities and differences in behavior. Also oddly, we credit about the same percentage (30 - 40%) of phenotypic variance separately to genes and to NSE. In contrast, shared environment (SE, environments that make people similar) often accounts for 0% (zero percent) of phenotypic variance.

We may give too much to the E in NSE. Siblings may differ because one of them had an older or a younger set of parents, an older or younger brother and different teachers than the other one. These are all aspects of NSE. However, the negligible, often temporary, contributions usually found for SE hint loudly that these aspects of NSE (e.g., differences in age of parents and birth order and teachers encountered) should also account for very little ... perhaps 1%.

Harris (1995) gave us a choice: she referred to NSE as "environmental variance of unknown origin" and attributed its effects to peer groups. Different friends make siblings different. Her assertion is no more convincing than the earlier one that differences in parents make us different. (Even Sulloway's conclusions (Sulloway, 1996) about birth order and family environment are unconvincing. First, the birth order effects, like those of SE, are only detectable with massive n and powerful statistics. Furthermore, there is an environmental confound: maternal fitness erodes with each child. Given less maternal investment, we would expect on the average a more driven quality to offspring behaviors, a prediction consistent in direction and magnitude with Sulloway's observations.)

Developmental noise and GenX-NSE

How else can we understand the phenotypic differences between MZT, differences that we now attribute to NSE? And what are the implications for us non twins?

First, there is NO allowance for "developmental noise" in these analyses. That is, identical genes in fruit flies, mice, and rats can be associated with very different phenotypes even in the same environment (Maynard Smith, 1998; Lewontin, 1998/2000). We have no estimates for developmental noise in humans and no estimates of noise by traits.

Second, NSE may be almost exclusively a genetic contribution! If genes bias our receptor and motivational systems then we become far more likely to detect some events but not others and to take some actions but not others. By this revised math, SE and a portion cleaved from NSE (Vinstructed? Rowe, 1999, applies the label "transmitted" for such environmental effects) now account for 0-2% of phenotypic variance. Genetic variance and the NSE variance that might be claimed by genes will jointly cover 60-80% of phenotypic variance.

While genes account for similarity within families (Plomin, et al., 2000), they also account for differences in those families. Developmental noise (only sometimes an environmental effect?) might account for much of the behavioral and physical difference between identical twins reared together.

Copyright, 2002, all rights reserved, James Brody.

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