Twins, Adoptees, Peers, Siblings study (TAPS)

About the TAPS Project

The Twins, Adoptees, Peers, and Sibling (TAPS) is a research project funded by the National Institute of Mental Health (MH-63350). It is a collaborative project between the University of San Francisco and California State University, Fullerton. The purpose of the study is to investigate sibling socialization processes in middle childhood. The study employs a novel design that includes monozygotic twins, dizygoic twins, full siblings, friends, and a new group called virtual twins (or same-aged, genetically-unrelated siblings). The TAPS design also allows us to investigate genetic and environment contributions to individual differences in behavior during this developmental period.

The TAPS team is indebted to the families that participated in the study. We would also like to thank the staff and students who assisted with previous phases of this project and USF and CSUF for their generous support of our research efforts.

Principal Investigators

University of San Francisco: Professor Shirley McGuire

Professor McGuire's research uses a biocontextual approach to study children's social and personality development and adjustment.

mcguire@usfca.edu
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California State University, Fullerton: Professor Nancy Segal

Professor Segal is director of the Twins Studies Center at CSUF. She studies genetic and environmental influences on behavior. She wrote a book on twins called Entwined Lives.

nsegal@fullerton.edu
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Publications

  • McGuire, S., & Shanahan, L., (2010). Sibling relationships in evolving family contexts. Child Development Perspectives, 4, 72-79.
  • McGuire, S., Segal, N. L., Gill, P., Whitlow, B., Clausen, J. M. (2010). Siblings and trust. In K. Rotenberg (Ed.), Interpersonal Trust during Childhood and Adolescence (pp. 133-154). Cambridge, UK: Cambridge University Press.
  • Conger, K. J, Stocker, C., & McGuire, S. (2009). Sibling socialization: The effects of stressful life events and experiences. In R. Larson (Ed.), New Directions in Child Development (pp. 45-59). Hoboken, NJ: Wiley.
  • Segal, N.L., Feng, R., McGuire, S., Allison, D.B., & Miller, S. (2008). Genetic and environmental contributions to body mass index: Comparative analysis of monozygotic twins, dizygotic twins and same-age unrelated siblings. International Journal of Obesity, 33, 37-41.
  • Segal, N. L., McGuire, S., Miller, S., & Havlena, J. (2008). Tacit coordination in monozygotic twins, dizygotic twins and virtual twins: Effects and implications of genetic relatedness.  Personality and Individual Differences, 45(7), 607-612.
  • Segal, N. L., McGuire, S., Havlena, J., Gill, P., & Hershberger, S. L. (2007). Intellectual similarity of virtual twin pairs: Developmental trends. Personality and Individual Differences, 42, 1209-1219.

Talks & Poster Presentations

  • Karnilowicz, H. R.*, Palaniappan, M.*, McCarthy, S.*, Larribas, T.*, Gross, M.*, & McGuire, S. (April 2012). Social competence and parental differential treatment across sibling dyads. Poster presented at the University of San Francisco 2nd Annual Student Research & Creativity Day of Celebration, San Francisco, CA.
  • Larribas, T.*, Gross, M.*, Palaniappan, M.*, Karnilowicz, H. R.*, McCarthy, S.*, & Segal, N. (April, 2012). Loneliness in middle childhood: Social connectedness and genetic relatedness. Poster presented at the 92nd annual convention of the Western Psychological Association, San Francisco, CA.
  • Palaniappan, M.*, Karnilowicz, H. R.*, McCarthy, S.*, Larribas, T.*, Gross, M.*, & McGuire, S. (April, 2012). Parental differential treatment: A twin-sibling-adoptee study. Poster presented at the 92nd annual convention of the Western Psychological Association, San Francisco, CA.
  • Baker, M. R.*, Larribas, T.*, Segal, N. L., McGuire, S., & Palaniappan, M.* (April, 2011). Friend or foe: Delinquency in twin and sibling dyads. Poster presented at the 91th annual convention of the Western Psychological Association, Los Angeles, CA.
  • McGuire, S., Palaniappan, M.*, Baker, M. R.*, Larribas, T.*, & Segal, N. L. (April, 2011). Heritability of parenting: Parent versus child perspective. Poster presented at the 91th annual convention of the Western Psychological Association, Los Angeles, CA.
  • *Foertsch, A., *Baker, M., Segal, N. & McGuire, S. (May, 2010). Sources of parental knowledge about children’s misbehavior and other activities. Poster presented at the 22nd annual meeting of the Association for Psychological Science, Boston, MA
  • *Baker, M., McGuire, S., Segal, N. & *Foertsch, A. (April, 2010). Sibling closeness, peer competence and loneliness in middle childhood. Poster presented at the 90th annual meeting of the Western Psychological Association, Cancun, Mexico.
  • *Foertsch, A., McGuire, S., Segal, N., & *Baker, Majel R. (April, 2010). You’ve got a friend in me: Sibling relationships and adjustment. Poster presented at the 90th annual meeting of the Western Psychological Association, Cancun, Mexico.
  • McGuire, S., Segal, N. L., *Baker, M., & *Foertsch, A. (May, 2009). Genetic contributions to effortful control in middle childhood. Poster presented at the 21st annual meeting of the Association for Psychological Science, San Francisco, CA.
  • *Foertsch, A., McGuire, S., *Baker, M., & Segal, N. (April, 2009). Closeness in Sibling Relationships: A Twin-Sibling Study. Poster presented at the 89th annual meeting of the Western Psychological Association, Portland, OR.
  • McGuire, S., Segal, N. L., & *Foertsch, A. (April, 2009). Sibling differences in exposure to peer delinquency and risky behavior: A twin-sibling-adoption design. In A. Pike (Chair), We haven’t given up: Developments in nonshared environment research. Symposium to be presented at the biennial meetings of the Society for Research in Child Development, Denver, CO.
  • McGuire, S. (April, 2009). Behavioral genetics. In K. Conger (Chair), Theoretical perspectives on sibling relationship dynamics. Roundtable discussion symposium to be presented at the biennial meetings of the Society for Research in Child Development, Denver, CO.
  • McGuire, S., Segal, N.L., *Gruen, J., & *Kuhn, H. (March, 2008). Symmetry in sibling trust. Poster to be presented at the Society for Research on Adolescence, Chicago, IL.
  • Segal, N.L., McGuire, S., Havlena, J., & Gill, P. (July, 2006). IQ Similarity in Virtual Twins: Developmental Trends. Poster presented at the Behavior Genetic Association, Storrs, CT.
  • McGuire, S., & Segal, N. L. (July, 2006). Peer network overlap in twin and sibling dyads. Poster presented at the International Society for the Study of Behavioural Development, Melbourne, Australia.
  • McGuire S., Gill, P., Whitlow, B., & Segal, N. L. (July, 2006). Sibling trustworthiness in four sibling contexts. Poster presented at the International Society for the Study of Behavioural Development, Melbourne, Australia.
  • McGuire, S., *Herold, K., Gill, P.R., *Whitlow, B. (April, 2006). Keeping secrets from mom: A twin-adoption studies of sibling trustworthiness. Poster to be presented at the biennial meetings of the Society for Research on Adolescences, San Francisco.
  • *Albrecht, A., & McGuire, S. (May, 2005). Peer exposure to delinquency: Examining links with parent and peer relationships. Poster presented at the annual Stanford Undergraduate Psychology Conference, Palo Alto, CA.
  • *Saso, C., & McGuire, S. (May, 2005). The relationships between sibling rivalry and trust. Poster presented at the annual Stanford Undergraduate Psychology Conference, Palo Alto, CA.
  • Segal, N.L., McGuire, S., Havlena, J., Davis, J., & Hershberger, S. (May, 2005). Virtual twins: What they have told us and what they may tell us about psychological development. Paper presented at the American Psychology Society, Los Angeles, CA.
  • Gill, P., *Whitlow, B., Davis, J., *Gonzalez, M., Segal, N. L., McGuire S. (April, 2005). Cooperative behavior in sibling relationships: A twin adoption study using the Prisoner's Dilemma. Poster presented at the biennial meetings of the Society for Research in Child Development, Atlanta, Georgia.
  • *Gordon, C., *Koo K., Havlena J., *Martin J., Segal N., McGuire S. (April, 2005). Behavior problems and well-being in adopted children: A twin design. Poster presented at the biennial meetings of the Society for Research in Child Development, Atlanta, Georgia.
  • *Kleinhenz, A. F., *Seghers, J., *Buzzard, M., *Williams, J., Segal, N. L., McGuire, S. (April, 2005). Children’s exposure to delinquent acts in middle childhood: A twin-sibling study. Poster presented at the biennial meetings of the Society for Research in Child Development, Atlanta, Georgia.
  • *Koo K., *Gordon C. F., Hobson L., *Kitchen-Britton K., Segal N. L., McGuire S., Do siblings have similar friends? A twin-adoption study. Poster presented at the biennial meetings of the Society for Research in Child Development, Atlanta, Georgia.
  • McGuire, S., Gill, P., Rotenberg, K., Segal, N. L., & *Betts, L. (April, 2005). Sibling trustworthiness: A twin-adoption study. Poster presented at the biennial meetings of the Society for Research in Child Development, Atlanta, Georgia.
  • McGuire, S., & Segal, N. (April, 2005). Parental differential treatment of siblings in three twin contexts: MZs, DZs, and VTs. In L. Shanahan (Chair), The ecologies of parental differential treatment of siblings. Symposium presented at the biennial meetings of the Society for Research in Child Development, Atlanta, Georgia.
  • McGuire, S. (2003). Parental differential treatment in different family contexts. Poster presented at the biennial meeting of the Society for Research in Child Development, Tampa, FL.
  • Manke, B., & McGuire, S. (2003). The importance of sibling relationships: Evidence from behavioral genetic studies. In S. McHale & K. Updegraff (Chairs), Siblings' Role in Family Socialization and Development. Symposium presented at the biennial meeting of the Society for Research in Child Development, Tampa, FL.
  • McGuire, S. (2002). What twins tell us about family dynamics. In S. McHale (Chair), Sibling Relationships: A Neglected Area in Family Research. Symposium presented at the annual National Conference on Family Relationships, Houston, TX.