T Bouchard - Academia.edu (original) (raw)

Papers by T Bouchard

Current Directions in Psychological Science, Aug 1, 2009

The heritability of human behavioral traits is now well established, due in large measure to clas... more The heritability of human behavioral traits is now well established, due in large measure to classical twin studies. We see little need for further studies of the heritability of individual traits in behavioral science, but the twin study is far from having outlived its usefulness. The existence of pervasive familial influences on behavior means that selection bias is always a concern in any study of the causal effects of environmental circumstances. Twin samples continue to provide new opportunities to identify causal effects with appropriate genetic and shared environmental controls. We discuss environmental studies of discordant twin pairs and twin studies of genetic and environmental transactions in this context.

Behavior genetics principles: Perspectives in development, personality, and psychopathology., 2004

Page 1. Acknowledgements Organizer: Douglas K. Detterman Case Western Reserve University Advisory... more Page 1. Acknowledgements Organizer: Douglas K. Detterman Case Western Reserve University Advisory Committee: ... 3:00-3:30 (19) Gilmore Symbol-Digit Substitution 3:00-3:30 (37) Nyborg IQ and g: Sex differences 3:30-3:45 – Break 3:30-3:45 – Break 3:30-3:45 – Break ...

Science, 1994

The idea that genetic factors influence behavior, including personality, is very old. The most co... more The idea that genetic factors influence behavior, including personality, is very old. The most compelling evidence has always been, as Darwin (1) noted, the successful domestication of animals. So in regard to mental qualities, their transmission is manifest in our dogs, horses and other domestic animals. Besides special tastes and habits, general intelligence, courage, bad and good tempers, etc., are certainly transmitted.

Psychological Inquiry, 1993

(1993). Creativity, Heritability, Familiarity: Which Word Does Not Belong? Psychological Inquiry:... more (1993). Creativity, Heritability, Familiarity: Which Word Does Not Belong? Psychological Inquiry: Vol. 4, No. 3, pp. 235-237.

Personality and Individual Differences, 1999

Historically, authoritarian attitudes have been attributed to in¯uences within the rearing enviro... more Historically, authoritarian attitudes have been attributed to in¯uences within the rearing environment, based on the incorrect assumption that similarity between family members demonstrates cultural transmission. To unconfound environmental and genetic in¯uences, this paper examines right-wing authoritarianism [RWA; Altemeyer, B. (1981). Right-wing authoritarianism. Winnipeg: University of Ottowa; Altemeyer, B. (1988). Enemies of freedom. San Francisco: Jossey-Bass Publishers] employing data from 39 monozygotic and 38 dizygotic adult reared apart twin pairs and 423 monozygotic and 434 dizygotic adult reared together twin pairs. Genetic factors accounted for about 50% and unshared environment for 35% of the phenotypic variance; either common environment or assortative mating could explain the remaining reliable variance. Similarity in cognitive ability did not underlie the twin correlations on authoritarianism. Purportedly relevant environmental variables from the Moos and Moos Family Environmental Scale (FES), the Block Environment Questionnaire (BEQ) and the MISTRA life history were associated with RWA scores for individuals reared by biological relatives; among adoptees, however, these variables are unrelated to RWA scores.

Personality and Individual Differences, 1993

Personality and Individual Differences, 1994

... WORK VALUES RICHARD D. ARVEY,&amp;#x27;&amp;#x27;* BRIAN P. MCCALL,1 THOMAS J... more ... WORK VALUES RICHARD D. ARVEY,&amp;#x27;&amp;#x27;* BRIAN P. MCCALL,1 THOMAS J. BOUCHARD JR,z PAUL TAUBMAN3 and MARCIE A. CAVANAUGH ... twins who were reared together, a common design used by researchers in behavioral genetics (Heath, Neale, Hewitt, Eaves Fulker ...

Psychological Medicine, 2007

BackgroundWhile the role of genetic factors in self-report measures of emotion has been frequentl... more BackgroundWhile the role of genetic factors in self-report measures of emotion has been frequently studied, we know little about the degree to which genetic factors influence emotional facial expressions.MethodTwenty-eight pairs of monozygotic (MZ) and dizygotic (DZ) twins from the Minnesota Study of Twins Reared Apart were shown three emotion-inducing films and their facial responses recorded. These recordings were blindly scored by trained raters. Ranked correlations between twins were calculated controlling for age and sex.ResultsTwin pairs were significantly correlated for facial expressions of general positive emotions, happiness, surprise and anger, but not for general negative emotions, sadness, or disgust or average emotional intensity. MZ pairs (n=18) were more correlated than DZ pairs (n=10) for most but not all emotional expressions.ConclusionsSince these twin pairs had minimal contact with each other prior to testing, these results support significant genetic effects on ...

American Psychologist, 1996

In the fall of 1994, the publication of Herrnstein and Murray's book The Bell Curve sparked a new... more In the fall of 1994, the publication of Herrnstein and Murray's book The Bell Curve sparked a new round of debate about the meaning of intelligence test scores and the nature of intelligence. The debate was characterized by strong assertions as well as by strong feelings. Unfortunately, those assertions often revealed serious misunderstandings of what has (and has not) been demonstrated by scientific research in this field. Although a great deal is now known, the issues remain complex and in many cases still unresolved. Another unfortunate aspect of the debate was that many participants made little effort to distinguish scientific issues from political ones. Research findings were often assessed not so much on their merits or their scientific standing as on their supposed political implications. In such a climate, individuals who wish to make their own judgments find it hard to know what to believe. Reviewing the intelligence debate at its meeting of November 1994, the Board of Scientific Affairs (BSA) of the American Psychological Association (APA) concluded that there was urgent need for an authoritative report on these issues-one that all sides could use as a basis for discussion. Acting by unanimous vote, BSA established a Task Force charged with preparing such a report. Ulric Neisser, Professor of Psychology at Emory University and a member of BSA, was appointed Chair. The APA Board on the Advancement of Psychology in the Public Interest, which was consulted extensively during this process, nominated one member of the Task Force," the Committee on Psychological Tests and Assessment nominated another," a third was nominated by the Council of Representatives. Other members were chosen by an extended consultative process, with the aim of representing a broad range of expertise and opinion. The Task Force met twice, in January and March of 1995. Between and after these meetings, drafts of the various sections were circulated, revised, and revised yet again. Disputes were resolved by discussion. As a result, the report presented here has the unanimous support of the entire Task Force. This is a "Report of a Task Force Established by the American Psychological Association." The Task Force appreciates the contributions of many members of the APA Board of Scientific Affairs (BSA) and the APA Board for the Advancement of Psychology in the Public Interest (BAPPI), who made helpful comments on a preliminary draft of this report. We also wish to acknowledge the indispensable logistical support of the APA Science Directorate during the preparation of the report itself.

Twin Research, 1999

This report presents findings for the Intrinsic (IR) and Extrinsic (ER) religiousness scales from... more This report presents findings for the Intrinsic (IR) and Extrinsic (ER) religiousness scales from the Minnesota Study of Twins Reared Apart. The scales were shown to be internally consistent, sufficiently distinct from the scales of the California Psychological Inventory and the Multidimensional Personality Questionnaire and unrelated to a number of measures of response style to justify treating them as distinct traits. The I scales also showed considerable evidence of construct validity in its correlations with religious fundamentalism and authoritarianism as assessed by the MMPI and Altemeyer's Right-Wing Authoritarianism scale. Data on IR and ER from 35 pairs of monozygotic twins reared apart (MZA) and 37 pairs of dizygotic twins reared apart (DZA) were fitted to a biometric model and demonstrated significant heritability (0.43 and 0.39), with a model containing genetic plus environmental factors fitting significantly better than a model containing only an environmental compo...

Science, 1990

In response to a number of inquiries concerming the proportion of genetic variance in IQ explaine... more In response to a number of inquiries concerming the proportion of genetic variance in IQ explained by the MZA [monozygotic] correlation, we have prepared the following explanation (Articles, 12 Oct., p. 223). It is a common misunderstanding that the intraclass correlation is squared to estimate the proportion of variance explained by genetic factors. Familial correlations represent components of variance; they are not squared (1). The reason that the intraclass correlation is not squared in our application is that the quantity to be estimated is the proportion of variance in twin A's IQ that is associated with twin A's genotype, and not the proportion of variance in twin A's IQ associated with twins B's IQ. In the latter case, an observed intraclass of 0.70 would be squared to yield an estimate of 0.49 for the proportion ofIQ variance shared by the two twins. In the former case, however, the observed phenotypes are imperfect indicators of the underlying genotypes, so that the correlation itself provides a direct estimate ofthe proportion ofIQ variance shared with the unobserved genotype. The situation is analogous to the estimation of reliability in psychometrics whereby the correlation between two parallel forms of a test provides a direct estimate of the proportion of observed test score variance associated with unobserved true score variance (that is, the reliability of the test) (2). THOMAS J. BoUCHARD, JR. Department ofPsychology, and Institute ofHuman Genetics, University ofMinnesota, Minneapolis, MN 55455 DAVID T. LYKKEN Department ofPsychology, University ofMinnesota, Minneapolis MATTHEw MCGUE Department ofPsychology, and Institute ofHuman Genetics, University ofMinnesota, Minneapolis NANCY L. SEGAL AuKE TELLEGEN Department ofPsychology, University ofMinnesota, Minneapolis Frazil Ice

Personality and Individual Differences, 2003

A 28 item version of the Wilson-Patterson Attitude Inventory was administered to 345 participants... more A 28 item version of the Wilson-Patterson Attitude Inventory was administered to 345 participants (twins, spouses, friends, and others) in the Minnesota Study of Twins Reared Apart. An overall conservatism measure demonstrated impressive construct validity. It had strong convergent validity, demonstrated by correlations of 0.72 and 0.58 with the Altemeyer Right Wing Authoritarianism scale and the Multidimensional Personality Questionnaire (MPQ) Traditionalism Scale, respectively. It also had strong discriminant validity, being largely uncorrelated with the other 10 MPQ Scales and WAIS Full Scale IQ. Heritabilities were calculated from fitting models to the variance-covariance matricies based on 54 pairs of monozygotic (MZ) and 46 pairs of dizygotic (DZ) twins reared apart. Conservatism demonstrated significant and sizeable genetic influence (h 2 =0.56), replicating the results reported in the Virginia 30,000 study of ordinary twins and family members and those of a large Australian twin study.