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Plain and Simple: On a Novel Feature of Amish

PersonalityMichael Weight and Henry Harpending

Department of AnthropologyUniversity of Utah

Salt Lake City, UT 84112, USA

October 10, 2014

Abstract

Positive assortative mating for a heritable trait or collection of

traits, selectively neutral with respect to the population, can be equiv-

alent to directional selection from the perspective of subgroups. This

can rapidly lead to genetic differences between subpopulations.

We examine consequences of this mechanism for North American

Amish, an Anabaptist population with little or no inward gene flow

but with substantial outward gene flow that has been declining in the

twentieth century. A standard personality assessment, the PF16, ad-

ministered to an Indiana population in 1970 shows nearly complete

divergence between Amish male adolescents and a sample of neigh-

boring non-Amish Indiana males. Without advocating or claiming a

genetic mechanism we show that a partially genetic model accountsclosely for the observed group differences and provides a baseline for

comparison with other transmission models.


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AmishMS/HCH/MW DRAFT Oct 2014

Introduction

Assortative mating can be equivalent to directional selection. Assortmentfor a trait generates either groups or a continuum within a population, thosewith more of the trait at one extreme and those with less of the trait at theother. To illustrate this consider a simple thought experiment of assortativemating about stature in a population average with average stature of 69inches for males and 64 inches for females, each with a standard deviationof 3 inches. These figures are are close to observed values in North America.Suddenly impose a mating rule such that those individuals taller than thepopulation mean mate only with others above the mean while individualsshorter than the mean mate only with others shorter than the mean. The

mean of a half-normal distribution is .8 standard deviations, so after theimposition of the new rule male and female stature in the tall group will be71.4 inches and 66.4 inches, respectively, and in the short group 67.6 inchesand 61.6 inches.

The new subpopulations now mate at random within within groups. Thetwo sets of parents differ by 5 inches in average stature, 69 (the average ofthe male mean of 71.4 inches and the female mean of 66.6 inches) in thetall subpopulation vs. 64 (the average of the male mean of 66.4 inches andthe female mean of 61.6) in the short subpopulation. After reproduction,assuming an additive heritability of .80 for stature, the group difference willbe .85 = 4 inches. If the mating rule persists, the tall and short populations

will continue to diverge, but at a decreasing rate. It is important to noticethat after the initial generation there is no further regression to the meansave for that in offspring of those who change groups. In other words, afterthe first generation of reproduction the genotypic group means differ by 4inches from then on in the absence of further movement between groups.Those who change groups prior to mating, for example tall offspring of theshort groups and short offspring of the tall group, will experience regressionto the mean (of their natal group) each generation.

Before the new mating system the standard deviation of stature was 3inches within each sex so the variance was the square of that, or 9 squaredinches. After a single generation of the new mating system the between-subpopulation variance is (3 0.8 0.8)2 or 3.69 inches squared. (The de-viation of each new subpopulation from the original mean, using males asan example, is the old standard deviation within the population, 3 inchesmultiplied by 0.8, to yield the change of the mean in the new subpopulation

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before reproduction, +0.8 3 in the new tall subpopulation and 0.8 3

in the new short subpopulation.) After reproduction regression to the oldmean occurs in each subpopulation so the deviation from the old mean be-comes 0.8 3 0.8 or 1.92 inches. The new squared deviation of the meanfrom the grand population mean is 1.922 or 3.69 squared inches, the newbetween-subpopulation variance. The new within-subpopulation variance is9 3.69 = 5.31 inches squared. After one generation the fraction of variancethat is between groups is 3.69/9, or approximately 41%.

Richard Lewontin (1972) famously estimated the fraction of genic vari-ance among continental human groups to be about 15% for a collection ofpresumably neutral genetic markers. That figure has remained about thesame as the number of such loci available to has has grown from dozens to

hundreds of thousands. After a single generation of our thought experimentthe stature variance between groups at genetic loci influencing stature is be-tween two and three times as great as overall neutral genic variance amongmajor human populations. Even though there is no selection or differentialreproduction in this experiment the consequence within groups is equivalentto truncation selection.

Ethnographic Analogues: The Old-Order Amish

Are there concrete ethnographic examples of assortative mating about a trait

analogous to height with the above kind of strong effect? There are sev-eral candidates. Cochran, Hardy, and Harpending (2006) proposed a similarmechanism in the evolution of Ashkenazi Jews of Europe during the MiddleAges: the Ashkenazim were a population closed to immigration, but with thepossibility of members leaving and they experienced strong selection for eco-nomic and managerial success. The Parsi of India, a closed class of mangers,scholars, musicians, and other economically and culturally successful individ-uals (Nelson, 2012), are another distinct population in which assortment mayhave been important in their evolution. Recently Charles Murray in ComingApart 2013 proposes that assortative mating by education, socioeconomicstatus, and IQ is splitting America into distinct and different classesthe

coming apart of the title.The Old-Order Amish in North America also follow the pattern of negli-

gible inward, but significant outward, gene flow, making them an attractivecandidate for selection by assortment. We describe a model in which thereis a underlying trait that we call AQor Amish Quotient by analogy with

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IQ as derived from cognitive tests. We postulate in this model that AQ is

predictive of the probability of an individual remaining in the communitywhen the choice is made at adolescence to remain and be baptized or todecline and emigrate. Specifically our measure of AQ, a collection of selfreported personality traits, is associated with the plain and simple lifestyleof the Amish, postulated to indicate an underlying affinity for, or attractive-ness of, membership in the community to an individual. Under the proposedmechanism of selection theAQwould increase each generation as those withlower AQs are truncated each generation through boilinig-off or defection.We therefore predict declining boiling-off rates over time are a consequenceof this selection mechanism increasing overall population Amishness (AQ)each generation.

The model performs well relative to alternative models of Amish defectionand retention (see Ericksenet al. (1980); Meyers (1991, 1994); Greksa (2002)for review). While Old-Order endogamy is well described and understood,the trade-offs and constraints of defection are unclear. Reductions in defec-tion rates over the last century (Greksa, 2002; Meyers, 1991, 1994; Kraybill,2001; Hostetler, 1993) need explanation, so any comprehensive model shouldalso account for this trend. Previous models of Amish defection emphasizerapid population growth in regions with finite resources, particularly expen-sive farm land, and the resultant trade-off between culturally sanctioned highfertility and the ability of families to support their own farms (Ericksen et al.

, 1980, 1979; Markle & Pasco, 1977; Wasao & Donnermeyer, 1996). Othermodels focus on effects of occupational shifts consequent to economic con-straints on farming. These models predict increasing exposure to non-Amishlifestyles may tempt youth into defection or interfere with parents abilityto transmit Amish identity (Meyers, 1991, 1994; Greksa, 2002). Unfortu-nately these more familiar approaches to the issue are difficult to quantifyand corroborate, and therefore wont be discussed further.

Old-Order Amish Endogamy

As the most traditional and plain Anabaptist group, the Old-Order Amish

are pacifists who reserve baptism for believing adults and have the strictestshunning practices of deviant church members (Hostetler, 1977, 1993; Roth,2002). Such non-hostile ethnocentrism and social solidarity introduce anear absolute boundary that culturally uncouples the Amish from the En-glish(their word for non-Amish) (Huntington, 1957; Savells, 1988). Familiar

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Amish norms like carrying intergroup discussions in Pennsylvania Dutch,

favoring horse-and-buggy over automobiles, traditional humble clothing, ab-solute pacifism, and forsaking appliances like telephones, televisions, refrig-erators, and indoor toilets are means to signal this un-coupling from theirbroader society (Kraybill, 2001; Fuchset al., 1990). Geneological and geneticanalysis reveals the Amish have been significantly isolated since Old-Orderfounding populations immigrated in the 18th and 19th Centuries (Leeet al.,2010; Pollinet al., 2007; Hostetler, 1993; Kraybill, 2001; Hurst & McConnell,2010). Arguably the Old-Order Amish are the most culturally isolated An-abaptist group in the United States (Hostetler, 1993; Kraybill, 2001; Nolt,1992).

Following this isolation the Old-Order substitute communal aide for sec-

ular public support. Initiatives like welfare, Social Security, life insurance,barn insurance (Hurd, personal communication), government agriculturalsubsidies, or public schools (if Amish schools are available) are therefore pro-hibited or strongly discouraged (Hostetler, 1969, 1993; Kraybill, 2001; Hurst& McConnell, 2010; Fuchs et al. , 1990) in the interests of communal self-reliance. Amish substitutes for institutional support are primarily mediatedthrough kin networks so extended families bear the emotional and financialburden of the welfare of their members (Hostetler, 1993; Hurst & McConnell,2010; Hurd, 1983). Children, especially males, rely on kin support to startbusinesses and farms when they begin their own families (Ericksen et al.

, 1980; Wasao & Donnermeyer, 1996; Ericksen et al. , 1979; Hurd, 1981).Highly fertile Amish mothers draw on relatives to help with their large fam-ilies (Hewner, 1998; Hurst & McConnell, 2010; Kraybill, 2001). Costs ofdisabled, ill, and senior members are mitigated by family and communitysupport (Hewner, 1998). The Amish are a healthy population with low inci-dence of infectious disease, low overall infant and adult mortality rates, highfertility, and high standards of living (Cross, 1969; Mckusick et al. , 1964;Fuchs et al. , 1990; Hewner, 1998; Greksa, 2002; Cross & McKusick, 1970;McKusick et al. , 1964).

16PFIn 1968 Paul Wittmer submitted a doctoral dissertation (Wittmer, 1968) atIndiana State University in which he aministered two psychological question-naires to 25 18-20 year old Amish young men and 25 young men of the sameage who were not Amish, all from Daviess County, Indiana. One question-

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naire had to do with relations of these men to their parents, but it apparently

not popularly used and so we have no comparative data about it. The otherwas a widely used personality assessment called 16PF (for 16 personalityfactors) that was developed in the 1940s by Raymond Cattell and others atthe University of Illinois (Cattell and Eber, 1972) and went through severalrevisions over the years. There are 180 questions on the form, from which areextracted 16 numbers supposed to represent the personality of the subjecton 16 dimensions of personality. These are listed in Table 1 along with theadjectives in common use that supposedly describe each measured trait.

We make no serious use of the details of the traits in this paper: wesimply regard the 16 numbers for each person in the study as self-reports ofinteresting characteristics. The test and the scoring system were designed to

maximize the independence of the factors so the scores are not redundantindicators of the same thing. In some of the literature factor B is not reportednor used since it is regarded as an assessment of intelligence rather than of apersonality trait. We include B with the other 15 since we treat these datain the same way that we would treat genetic markers such as SNPS, i.e. weare agnostic about the interpretation and meaning of the factors.

Scores on personality assessments are substantially heritable (Turkheimeret al. , 2014; Cattell et al. , 1985). This means that if there is selectionthat affects any of them then they should change over time. Our textbooksordinarily define additive heritability as the fraction of variance of a trait that

is caused by additive gene effects. Plant and animal breeders, on the otherhand, assess heritability by the response to selection. If the ideal quantitativegenetic model is a satisfactory description of the trait and the organism, thesedefinitions of heritability are the same.

Heritability in the human sciences has been curiously unapparent sincethe middle of the twentieth century. With some exceptions it has been reso-lutely ignored and occasionally viewed with revulsion, as if it would go awayif never mentioned. This was a consequence of the twentieth century strongsocial science (Boasian) fad maintaining that human biology and humanbehavior must be uncoupled. There were routine denunciations of heritabilitystudies (e.g. Kamin & Goldberger, 2002) picking at various possible weak-

nesses. For example much data on identical and fraternal twins, separated atbirth or not, was collected. These showed essentially that the environmentin which a child was raised had little effect on the development of the childwhile shared genes had a large effect. A valid criticism was that twins hadshared the same uterine environment for the 9 months of mothers pregnancy

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Trait Label High Low

A Outgoing ReservedWarmhearted Detached

B Abstract thinking Concrete thinkingFast learner Slow learner

C Unemotional EmotionalCalm Changeable

E Assertive HumbleDominant Cooperative

F Cheerful SoberLively Taciturn

G Conscientious ExpedientPersistent Undisciplined

H Venturesome ShySocially bold Retiring

I Tough-minded Tender-mindedSelf-reliant Sensitive

L Suspicious TrustingSceptical Accepting

M Imaginative PracticalBohemian Conventional

N Shrewd ForthrightDiscreet Straightforward

O Guilt-prone ResilientWorrying Self-assured

Q1 Radical ConservativeExperimental Traditional

Q2 Self-sufficient Group-dependentResourceful Affiliative

Q3 Controlled UndisciplinedCompulsive Lax

Q4 Tense Relaxed

Driven Tranquil

Table 1: The 16 traits derived from the 16PF assessment with the adjectives thatconventionally describe each. We use these simply as anonymous markers of responsesto diverse questions by the subjects of the study.

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among subjects computed over all the traits. The distances would sit in a 15

dimensional space since there are only 16. Because there are only 16 traits,the distances among the 50 subjects also sits in a 15 dimensional space, ratherthan 49, and these spaces have essentially the same dimensions. They aresaid to be dual to each other.

Since we cant visualize the data in all their 15 dimensional splendor welose some information by looking only at a two-dimensional slice through theswarm. This slice is computed so that the disperal of subjects or traits alongits first dimension is maximized and along its second dimension is maximizedafter the first dimension is removed. Of course we could build a model oreven a picture of the best 3 dimensions rather than just two but thse modelshardly even provide much insight.

This procedure is called PCA (Principal Components Analysis), but no-tice that we want to look at two spaces rather than just one. The subjectsspace plots principal components and the trait space plots principal coor-dinates: we look at them simultaneously to visualize patterns in the data.(Look at the two panels of figure 1 or figure 2, which is the easiest way tomake sense of the last sentence.) Further, by analogy with cognitive tests,we will refer to the first (largest) dimension as the AQor Amish Quotient.This is, for each subject, in our model, an estimate of how Amish that personis, meaning what that persons score on our Amish quotient.

The process we are using is analogous to that of estimating IQ. Although

there is some disagreement, an important finding from cognitive testing isthat cognitive ability is essentially one-dimensional. People with high math-ematical ability also have large vocabularies, and so on. One empirical resultof this is that almost anything we construct functions as an IQ test or a proxyfor a proper IQ test. SATs, GREs, MCATs, and AFQTs, are nearly inter-changeable with IQ tests. The United States General Social Survey (GSS)surveys a large sample of Americans every few years. The results are con-veniently available on the web (General Social Survey, 2012). Among manyquestions on the GSS, each round presents the respondent with ten wordsand ask for their definitions. The tabulated variable, called WORDSUM,varies from 0 to 10. This is a useful proxy for IQ in the sense that differences

among groups in WORDSUM replicate closely reported differences amongthe same groups from more elaborate tests.

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Results from 16PF

Scattergrams of groups and traits, that is principal components and principalcoordinates, from 16PF are shown in figures 1 and 2. Figure 1 shows patternsamong groups means, the Amish and non-Amish from Wittmers study alongwith a collection of other populations culled from the literature. Details aregiven in the caption of figure 1. The scatter of traits, in the left panel, is notvery informative. There is no clear pattern, reflecting presumably the designgoal of independence among the 16 factors. The scatter among groups, inthe right panel, is more interesting. There are three groups that are on theedge of the scatter: Amish, Chinese nurses, and candidates for high levelmanagement positions in the UK. The outstanding (AN) and ordinary (EN)

Chinese nurses are nearly identical to each other on these first two dimensions(Zhanget al. , 2013). Generic English (UK) are world-average and are moresimilar to Indiana farm boys than they are to high level managers in the UK(Bartram, 1992).

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Figure 1: PCA of 16PF score differences among groups. The left panel portrays sim-ilarities among the 16 traits (see Table 1). The right panel portrays differences amongsamples. AM are young Amish males from Indiana, IN are your non-Amish males fromIndiana, AN and EN are outstanding and ordinary Chinese nurses respectively, MK arecandidates for high level manager jobs in the UK, and UK are UK norms. Notice thelack of pattern in the left panel, indicating the relative independence of the 16 traits.

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The purpose of figure 1 is to convey a picture of global group differences

but our real interest is in figure 2 showing in detail individual differencesamong young rural Indiana men. The scatter shows a nearly complete dis-

junction between the Amish and non-Amish along the horizonta axis, that is,the first principal component. For comparison the UK mean is shown in theright panel as the large letter U in green. Remarkably the overall UK meanis in the center of the non-Amish scatter implying that they are not verydifferent. The Amish, in the scatter, are strongly different. In our model thedifferences are the accumulated effects of Amish voluntary endogamy alongwith boiling off of young Amish each generation who decide to leave theAmish community.

The left panel of figure 1, the scatter of traits, helps identify those traits

that distinguish Amish and non-Amish. On the extreme left of the hori-zontal axis, in the space of those with highest AQ, are traits G, Q3, andI. The scoring of the 16PF questionnaire shows that Amish describe them-selves, albeit indirectly, as conscientious and persistent (G), tough-mindedand self-reliant (I), and controlled and even compulsive (Q3). Correspond-ingly they describe themselves as low in Q1 and E, that is as conservativeand traditional (low Q1) and humble and cooperative (low E). These im-puted self-characterizations are in remarkable agreement with stereotypes ofthe Amish that they hold themselves according to ethnographies. We our-selves are agnostic about the meaning and uses of tests such as these except

as indirect self-descriptions by subjects.

A Model of (Self-)Selection

Under our model the horizontal axis in figure 2 is a scale, called AQ, esti-mating Amishness meaning where on a numeric scale an individual is ina suite of traits that differentiate young Amish men from their non-Amishneighbors. Since movement out of the Amish community is open to anyone,especially around the age of adolescence, what would be the consequencesfor the Amish community if individuals on the low end of AQ were especiallyprone to leave the population?

Without proposing that Amish boiling off does reflect gene differences, itis informative to bring a quantitative genetics model to the phenomenon asa well understood baseline for evaluating competing models. We assume inthis spirit that AQ is a partially heritable trait. We have enough data onbehavioral or psychological trait heritabilities to use an estimate of additive

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Figure 2: PCA of individual 16 PF scores. The left panel portrays similarities amongtraits, the right panel among individuals along with the overall UK population. Amishyoung me are shown as red As, non-Amish as blue Is, and the large green U showsthe centroid of the UK standard for comparison. The two panels are dual, so proximitybetween a trait in the left panel and a subject in the right indicates a high value of thattrait in that subject. For example the Amish subjects have high values of 16PF traitG, which is called conscientiousness and persistence in the literature. Non-Amishyoung Indiana males have relatively higher scores on trait Q1, called Radical andExperimental.

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heritability of AQ, conventionally written h2 of 0.5. Boiling off rates vary

among communities: a reasonable contemporary value is 0.10 meaning thatten percent of youth chose to leave the community. From the ethnographiesit does not appear that this is youthful rebellion but instead a thought-outchange. Many join neighboring Mennonite groups for example.

Following standard practice in quantitative genetics we now assume thatAQ has an underlying normal or Gaussian distribution in the Amish pop-ulation and that the ten percent boiling off rate is equivalent to losing thebottom ten percent of the distribution each generation. We are assuming thatthe boiling off mechanism is equivalent to truncation selection, but other se-lection schemes will have an some equivalent truncation point that can becomputed.

With ten percent with the lowestAQleaving each generation, the averageAQ of those who remain is 0.20 standard deviations if the the populationmean before emigratioin was 0. In other words this amount of self-selectiveemigration leaves behind a population whose average AQ is 0.2 standarddeviations greater than it was before the emigration. We now assume thatmating occurs exclusively within the Amish. We assume that the heritabilityof AQ is 0.5 meaning that the offspring will regress halfway back to theparental mean.

The next generation of children will have an average AQof 0.10 standarddeviations greater than their parents did before emigration. The process of

selective emigration repeats so that the mean Amish AQ increases by onetenth of a standard deviation per generation. With 25 years per generation,Amishness will increase by a full standard deviation in 10 generationsor 250 years. This is substantial social evolution on a time scale of a fewcenturies.

Our AQof an individual is simply the value of that individual along thex-axis of the right panel of figure 2. The computed standard deviations ofAQfor the Amish and non-Amish subjects are 1.33 and 1.31 respectively, so wecan take the within group standard deviation to be 1.32 units. The meansof the two groups are 1.4 and 1.4 units respectively and the difference,the distance between the two groups, is 2.8 units, slightly more than two

standard deviations. This may suggest that the heritability ofAQ is higherthan our assumed 0.5, that the rate of boiling off was higher in the past,for which there is support, or that the process has been going on longerthan ten generations. This last possibility is unlikely. Currently no Old-Order exist in Europe. Persecution and political sanctions in the 17th and

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18th Centuries had spread European Amish families too far apart to form

cohesive communities, forcing early European Amish to eventually assimilatewith non-Amish (Roth, 2002; Hostetler, 1977; Crowley, 1978; Nolt, 1992;Gascho, 1937). Thus the magnitude of Amish endogamy was likely negligiblein Europe compared to Amish endogomous mating in the United States, sothe Old-Order tenure in Europe likely hasnt contributed to the differencesreported here.

Conclusion

Quantitative genetic theory is well established in agriculture and in areas ofbiology like biometrics and conservation biology. It deserves more attention

and use in the rest of evolutionary biology. We have shown that a simplequantitative genetic model of a trait that is only partially heritable providesa clean fit to a small set of personality test data from over four decades ago.

Our fit does not confirm the quantitative genetic model. Some othermechanism may fit the data as well or better. In particular purely culturaltransmission might generate this pattern, with no genetic consequence atall. At this point the value of our approach becomes apparent since thereis no such cultural transmission model, only prose about plausibilities andpossibilities. In other words our model clarifies the mechanisms and magni-tudes required of a purely cultural model. The difference between the two

groups of subjects corresponds to the consequences of several centuries ofmild selection by choice of membership in an otherwise closed group.

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References

Bartram, Dave. 1992. The personality of UK managers: 16PF norms forshort-listed applicants. Journal of Occupational and Organizational Psy-chology,65(2), 159172.

Cattell, Raymond B, Rao, DC, et al. . 1985. Heritability in the personalitycontrol system: Ego strength (C), super ego strength (G) and the selfsentiment (Q3); by the MAVA Model, Q-Data, and maximum likelihoodanalyses.Social Behavior and Personality: an international journal,13(1),3341.

Cochran, G., Hardy, J., & Harpending, H. 2006. Natural history of Ashkenazi

intelligence. Journal of Biosocial Science, 38, 659693.

Cross, Harold. 1969. Some demographic characteristics of Amish society.Pages 126 of: Hostetler, John (ed), Conference on Child Socialization.

Cross, Harold E, & McKusick, Victor A. 1970. Amish demography. Biode-mography and Social Biology,17(2), 83101.

Crowley, William K. 1978. Old Order Amish settlement: diffusion andgrowth. Annals of the Association of American Geographers, 68(2), 249264.

Davies, G., Tenesa, A., Payton, A., Yang, J., Harris, S. E., Liewald, D., Ke,X., Le Hellard, S., Christoforou, A., Luciano, M., et al. . 2011. Genome-wide association studies establish that human intelligence is highly herita-ble and polygenic. Molecular psychiatry,16(10), 9961005.

Ericksen, Eugene P, Ericksen, Julia A, & Hostetler, John Andrew. 1980. Thecultivation of the soil as a moral directive: population growht, family ties,and the maintenance of community among the Old Order Amish. RuralSociology.

Ericksen, Julia A, Ericksen, Eugene P, Hostetler, John A, & Huntington,

Gertrude E. 1979. Fertility patterns and trends among the Old OrderAmish. Population Studies, 33(2), 255276.

Fuchs, Janet A, Levinson, Richard M, Stoddard, Ronald R, Mullet, Mau-rice E, & Jones, Diane H. 1990. Health risk factors among the Amish:results of a survey. Health Education & Behavior,17(2), 197211.

15


17/19


Gascho, Milton. 1937. The Amish Division of 1693-1697 in Switzerland and

Alsace. Mennonite Historical Society.

General Social Survey. 2012. http://www3.norc.org/GSS+Website/. ac-cessed 05/08/14.

Greksa, Lawrence P. 2002. Population growth and fertility patterns in anOld Order Amish settlement. Annals of Human Biology,29(2), 192201.

Hewner, Sharon J. 1998. Fertility, migration, and mortality in an Old OrderAmish community. American Journal of Human Biology,10(5), 619628.

Hostetler, John A. 1977. Old Order Amish Survival. Mennonite Quarterly

Review.Hostetler, John A. 1993. Amish society. JHU Press.

Hostetler, John Andrew. 1969. Educational Achievement and Life Styles inTraditional Society: The Old Order Amish. US Department of Health,Education, and Welfare, Office of Education, Bureau of Research.

Huntington, Gertrude Enders. 1957. Dove at the window: a study of an OldOrder Amish community in Ohio. Ph.D. thesis, Yale University.

Hurd, James. 1981. Mate choice among the Nebraska Amish of Central Penn-

sylvania. Ph.D. thesis, Pennsylvania State University.Hurd, James P. 1983. Kin relatedness and church fissioning among the Ne-

braska Amish of Pennsylvania. Biodemography and Social Biology,30(1),5966.

Hurst, Charles E, & McConnell, David L. 2010. An Amish paradox: Diversityand change in the worlds largest Amish community. JHU Press.

Kamin, Leon J, & Goldberger, Arthur S. 2002. Twin studies in behavioralresearch: a skeptical view. Theoretical Population Biology,61(1), 8395.

Kraybill, Donald B. 2001. The riddle of Amish culture. JHU Press.

Lee, Woei-Jyh, Pollin, Toni I, OConnell, Jeffrey R, Agarwala, Richa, &Schaffer, Alejandro A. 2010. PedHunter 2.0 and its usage to characterizethe founder structure of the Old Order Amish of Lancaster County. BMCmedical genetics, 11(1), 68.

16


18/19


Lewontin, R. C. 1972. The apportionment of human diversity. Evolutionary

biology,6(38), 1398.

Markle, Gerald E., & Pasco, Sharon. 1977. Family limitation among the OldOrder Amish. Population Studies,31(2), 267280.

McKusick, Victor A, Hostetler, John A, Egeland, Janice A, & Eldridge,Roswell. 1964. The distribution of certain genes in the Old Order Amish.Pages 99114 of: Cold Spring Harbor symposia on quantitative biology,vol. 29. Cold Spring Harbor Laboratory Press.

Mckusick, Victor A, Hostetler, John A, & Egeland, Janice A. 1964. Geneticstudies of the Amish. Bulletin of the Johns Hopkins Hospital, 115, 203222.

Meyers, Thomas J. 1991. Population growth and its consequences in theElkhart-LaGrange Old Order Amish settlement. Mennonite Quarterly Re-view.

Meyers, Thomas J. 1994. The Old Order Amish: To remain in the faith orto leave. Mennonite Quarterly Review,68(3), 378395.

Murray, Charles. 2013. Coming Apart: The State of White America, 1960-2010. Random House LLC.

Nelson, Dean. 2012 (October). Indias dwindling Parsipopulation to be boosted with fertility clinics. www.telegraph.co.uk/news/worldnews/asia/india/9612009/

Indias-dwindling-Parsi-population-to-be-boosted-with-fertility-clinics.

html.

Nolt, Steven M. 1992. A History of the Amish. Good Books Intercourse, PA.

Pollin, Toni I, McBride, Daniel J, Agarwala, Richa, Schaffer, Alejandro A,Shuldiner, Alan R, Mitchell, Braxton D, & OConnell, Jeffrey R. 2007.Investigations of the Y chromosome, male founder structure and YSTRmutation rates in the Old Order Amish. Human heredity, 65(2), 91104.

Roth, John D. 2002. Letters of the Amish Division: A Sourcebook.

17


19/19


Savells, Jerry. 1988. Economic and social acculturation among the Old Order

Amish in select communities: Surviving in a high-tech society. Journal ofComparative Family Studies, 123135.

Turkheimer, Eric. 2011. Still missing. Research in Human Development,8(3-4), 227241.

Turkheimer, Eric, Pettersson, Erik, & Horn, Erin E. 2014. A Phenotypic NullHypothesis for the Genetics of Personality. Annual Review of Psychology,65(1), 515540.

Visscher, Peter M, Hill, William G, & Wray, Naomi R. 2008. Heritability inthe genomics eraconcepts and misconceptions. Nature Reviews Genetics,9(4), 255266.

Wasao, Samson W, & Donnermeyer, Joseph F. 1996. An analysis of factorsrelated to parity among the Amish in northeast Ohio. Population Studies,50(2), 235246.

Wittmer, Paul Joseph. 1968. A comparison of the variability of perceivedparental behavior characteristics and personality traits of twenty-five non-

Amish and twenty-five Amish male youth, between the ages of eighteen and

twenty, from the same community. Ph.D. thesis, Indiana State University.

Yang, Jian, Benyamin, Beben, McEvoy, Brian P, Gordon, Scott, Henders,Anjali K, Nyholt, Dale R, Madden, Pamela A, Heath, Andrew C, Martin,Nicholas G, Montgomery, Grant W, et al. . 2010. Common SNPs explaina large proportion of the heritability for human height. Nature genetics,42(7), 565569.

Zhang, Li, Liu, Bo, Ren, Hui, Liu, Yu-Fu, & Zhang, Yan. 2013. The person-ality profile of excellent nurses in China: The 16PF. Contemporary Nurse:A Journal for the Australian Nursing Profession,43(2), 219.

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