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Heritability of children's prosocial behavior and differential susceptibility to parenting by variation in the dopamine receptor D4 gene

Published online by Cambridge University Press:  24 January 2011

Ariel Knafo ,
Salomon Israel  and
Richard P. Ebstein
Ariel Knafo*
Affiliation:
Hebrew University of Jerusalem
Salomon Israel
Affiliation:
National University of Singapore
Richard P. Ebstein
Affiliation:
Hebrew University of Jerusalem National University of Singapore
*
Address correspondence and reprint requests to: Ariel Knafo, Psychology Department, Hebrew University of Jerusalem, Mount Scopus, Jerusalem 91905, Israel; E-mail: msarielk@mscc.huji.ac.il.
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Abstract

Theoretical considerations and new empirical evidence suggest that children's development cannot simply be explained by either genes or environment but that their interaction is important to understanding child behavior. In particular, a genetic polymorphism, the exon III repeat region of the dopamine receptor D4, has been the focus of interest regarding differential susceptibility to parental influence. To study environmental and genetic influences on children's prosocial behavior, 168 twin pairs (mean age = 44 months) participated in an experiment that assessed prosocial behavior via three measures: compliant prosocial behavior elicited in response to social requests, self-initiated prosocial behavior enacted voluntarily, and mothers' rating of children's behavior. Genetic effects accounted for 34% to 53% of the variance in prosocial behavior. The rest of the variance was accounted for by nonshared environment and error. Parenting measures of maternal positivity, negativity, and unexplained punishment did not correlate significantly with children's prosocial behavior. However, when parenting was stratified by presence or absence of the child's dopamine receptor D4 7-repeat allele in an overlapping sample of 167 children to model differential susceptibility to parental influence, a richer picture emerged. Positive parenting related meaningfully to mother-rated prosocial behavior, and unexplained punishment related positively to self-initiated prosocial behavior, but only among children carrying the 7-repeat allele. The findings demonstrate that a molecular genetic strategy, based on genotyping of common polymorphisms and combined with a classic twin approach, provides a richer description of how genes and environment interact to shape children's behavior, and allows for the identification of differential sensitivity to parental influence.

Type
Special Section Articles
Information
Development and Psychopathology , Volume 23 , Issue 1 , February 2011 , pp. 53 - 67
Copyright
Copyright © Cambridge University Press 2011

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References

Asbury, K., Dunn, J. F., Pike, A., & Plomin, R. (2003). Nonshared environmental influences on individual differences in early behavioral development: A monozygotic twin differences study. Child Development, 74, 933–943.Google Scholar
Asghari, V., Sanyal, S., Buchwalt, S., Paterson, A., Jovanovic, V., & Van Tol, H. H. (1995). Modulation of intracellular cyclic AMP levels by different human dopamine D4 receptor variants. Journal of Neurochemistry, 65, 1157–1165.CrossRefGoogle ScholarPubMed
Bachner-Melman, R., Gritsenko, I., Nemanov, L., Zohar, A. H., & Ebstein, R. P. (2005). Dopaminergic polymorphisms associated with self-report measures of human altruism: A fresh phenotype for the dopamine D4 receptor. Molecular Psychiatry, 10, 333–335.Google Scholar
Bakermans-Kranenburg, M. J., & van IJzendoorn, M. H. (2006). Gene–environment interaction of the dopamine D4 receptor (DRD4) and observed maternal insensitivity predicting externalizing behavior in preschoolers. Developmental Psychobiology, 48, 406–409.Google Scholar
Bakermans-Kranenburg, M. J., & van IJzendoorn, M. H. (2007). Research review: Genetic vulnerability or differential susceptibility in child development: The case of attachment. Journal of Child Psychology and Psychiatry, 48, 1160–1173.CrossRefGoogle ScholarPubMed
Bakermans-Kranenburg, M. J., & van IJzendoorn, M. H. (2009). Differential susceptibility to rearing environment depending on dopamine-related genes: Children's donating to UNICEF. Paper presented at the Society for Research in Child Development Meeting, Denver, CO.Google Scholar
Bakermans-Kranenburg, M. J., van IJzendoorn, M. H., Pijlman, F. T. A., Mesman, J., Juffer, F. (2008). Experimental evidence for differential susceptibility: Dopamine D4 receptor polymorphism (DRD4 VNTR) moderates intervention effects on toddlers' externalizing behavior in a randomized controlled trial. Developmental Psychology, 44, 293–300.CrossRefGoogle ScholarPubMed
Bar-Tal, D. (1982). Sequential development of helping behavior: A cognitive–learning approach. Developmental Review, 2, 101–124.Google Scholar
Batson, C. D. (2009). Empathy-induced altruistic motivation. In Shaver, P. R. & Mikulincer, M. (Eds.), Prosocial motives, emotions, and behavior (pp. 15–34). Washington DC: American Psychological Association.Google Scholar
Belsky, J. (1997). Variation in susceptibility to environmental influence: An evolutionary argument. Psychological Inquiry, 8, 182–186.Google Scholar
Belsky, J., Bakermans-Kranenburg, M. J., & van IJzendoorn, M. H. (2007). For better and for worse: Differential susceptibility to environmental influences. Current Directions in Psychological Science, 16, 300–304.Google Scholar
Belsky, J., Hsieh, K., & Crnic, K. (1998). Mothering, fathering, and infant negativity as antecedents of boys' externalizing problems and inhibition at age 3 years: Differential susceptibility to rearing experience? Development and Psychopathology, 10, 301–319.Google Scholar
Belsky, J., & Pluess, M. (2009a). The Nature (and nurture?) of plasticity in early human development. Perspectives on Psychological Science, 4, 345–351.CrossRefGoogle ScholarPubMed
Belsky, J., & Pluess, M. (2009b). Beyond diathesis stress: Differential susceptibility to environmental influences. Psychological Bulletin, 135, 885–908.CrossRefGoogle ScholarPubMed
Benenson, J. F., Pascoe, J., & Radmore, N. (2007). Children's altruistic behavior in the dictator game. Evolution and Human Behavior, 28, 168–175.CrossRefGoogle Scholar
Benish-Weisman, M., Steinberg, T., & Knafo, A. (2010). Genetic and environmental links between children's temperament and their problems with peers. Israel Journal of Psychiatry, 47, 144–151.Google ScholarPubMed
Benjamin, J., Li, L., Patterson, C., Greenberg, B. D., Murphy, D. L., & Hamer, D. H. (1996). Population and familial association between the D4 dopamine receptor gene and measures of Novelty Seeking. Nature Genetics, 12, 81–84.CrossRefGoogle ScholarPubMed
Boyce, W. T., Chesney, M., Alkon, A., Tschann, J. M., Adams, S., Chesterman, B., et al. (1995). Psychobiologic reactivity to stress and childhood respiratory illnesses: Results of two prospective studies. Psychosomatic Medicine, 57, 411–422.CrossRefGoogle ScholarPubMed
Boyce, W. T., &, Ellis, B. J. (2005). Biological sensitivity to context: I. An evolutionary-developmental theory of the origins and functions of stress reactivity, Development and Psychopathology, 17, 271–301.Google Scholar
Burt, S. A. (2008). Genes and popularity: Evidence of an evocative gene–environment correlation. Psychological Science, 19, 112–113.Google Scholar
Canli, T. (2008). Toward a “molecular psychology” of personality. In John, O. P., Robins, R. W., & Pervin, L. A. (Eds.). Handbook of personality: Theory and research (pp. 311–327). New York: Guilford Press.Google Scholar
Carlo, G., Roesch, S. C., & Melby, J. (1998). The multiplicative relations of parenting and temperament to prosocial and antisocial behaviors in adolescence. Journal of Early Adolescence, 18, 266–290.Google Scholar
Caspi, A., McClay, J., Moffitt, T. E., Mill, J., Martin, J., Craig, W. I., et al. (2002). Role of genotype in the cycle of violence in maltreated children. Science, 297, 851–854.Google Scholar
Caspi, A., Moffitt, T. E., Morgan, J., Rutter, M., Taylor, A., Arseneault, L., et al. (2004). Maternal expressed emotion predicts children's antisocial behavior problems: Using monozygotic-twin differences to identify environmental effects on behavioral development. Developmental Psychology, 40, 149–161.Google Scholar
Cesarini, D., Dawes, C. T., Johannesson, M., Lichtenstein, P., & Wallace, B. (2009). Experimental game theory and behavior genetics. Annals of the New York Academy of Sciences, 1167, 66–75.CrossRefGoogle ScholarPubMed
Cicchetti, D., & Dawson, G. (2002). Multiple levels of analysis [Editorial]. Development and Psychopathology, 14, 417–420.CrossRefGoogle ScholarPubMed
Clark, K. E., & Ladd, G. W. (2000). Connectedness and autonomy support in parent–child relationships: Links to children's socioemotional orientation and peer relationships. Developmental Psychology, 36, 485–498.Google Scholar
David, S. P., & Munafo, M. R. (2008). Genetic variation in the dopamine pathway and smoking cessation. Pharmacogenomics, 9, 1307–1321.CrossRefGoogle ScholarPubMed
DeCoster, J. (2007). Applied linear regression notes set 1. Retrieved March 3, 2005, from http://www.stat-help.com/notes.htmlGoogle Scholar
De Waal, F. B. M. (2008). Putting the altruism back into altruism: The evolution of empathy. Annual Review of Psychology, 59, 279–300.Google Scholar
DiLalla, L. F., Elam, K. K., & Smolen, A. (2009). Genetic and gene–environment interaction effects on preschoolers' social behaviors. Developmental Psychobiology, 51, 451–464.Google Scholar
Durston, S., Fossella, J. A., Casey, B. J., Hulshoff Pol, H. E., Galvan, A., Schnack, H. G., et al. (2005). Differential effects of DRD4 and DAT1 genotype on fronto-striatal gray matter volumes in a sample of subjects with attention deficit hyperactivity disorder, their unaffected siblings, and controls. Molecular Psychiatry, 10, 678–685.Google Scholar
Ebstein, R. P., Novick, O., Umansky, R., Priel, B., Osher, Y., Blaine, D., et al. (1996). Dopamine D4 receptor (D4DR) exon III polymorphism associated with the human personality trait of Novelty Seeking. Nature Genetics, 12, 78–80.Google Scholar
Eisenberg, N. (2004). The early development of prosocial tendencies. In Leavitt, L. A. & Hall, D. M. B. (Eds.), Social and moral development: Emerging evidence on the toddler years. New Brunswick, NJ: Johnson & Johnson Pediatric Institute, L.L.C.Google Scholar
Eisenberg, N., Cameron, E., & Tryon, F. (1984). Prosocial behavior in the preschool years: Methodological and conceptual issues. In Staub, E., Bar-Tal, D., Karylowski, J., & Reykowski, J. (Eds.), The development and maintenance of prosocial behavior: International perspectives on positive development (pp. 101–115). New York: Plenum Press.Google Scholar
Eisenberg, N., Fabes, R. A., & Spinrad, T. (2006). Prosocial development. In Eisenberg, N. (Vol. Ed.) & Damon, W. & Lerner, R. M. (Series Eds.), Handbook of child psychology: Vol. 3. Social, emotional, and personality development (6th ed., pp. 646–718). Hoboken, NJ: Wiley.Google Scholar
Eisenberg, N., Pasternack, J. F., Cameron, E., & Tryon, K. (1984). The relation of quantity and mode of prosocial behavior to moral cognitions and social style. Child Development, 55, 1479–1485.Google Scholar
Eisenberg, N., Wolchik, S. A., Goldberg, L., & Engel, I. (1992). Parental values, reinforcement, and young children's prosocial behavior: A longitudinal study. Journal of Genetic Psychology, 153, 19–36.CrossRefGoogle Scholar
Ellis, J., & Boyce, T. (2008). Biological sensitivity to context. Current Directions in Psychological Science, 17, 183–187.Google Scholar
Ellis, B. J., Boyce, W. T., Belsky, J., Bakermans-Kranenburg, M. J., & van IJzendoorn, M. H. (2011). Differential susceptibility to the environment: An evolutionary–neurodevelopmental theory. Development and Psychopathology, 23, 7–28.Google Scholar
Fan, J., Fossella, J., Sommer, T., Wu, Y., & Posner, M. I. (2003). Mapping the genetic variation of executive attention onto brain activity. Proceedings of the National Academy of Sciences of the United States of America, 100, 7406–7411.CrossRefGoogle ScholarPubMed
Gervai, J., Nemoda, Z., Lakatos, K., Ronai, Z., Toth, I., Ney, K., et al. (2005). Transmission disequilibrium tests confirm the link between DRD4 gene polymorphism and infant attachment. American Journal of Medical Genetics, 132B, 126–130.Google Scholar
Gillespie, N. A., Cloninger, C. R., Heath, A. C., & Martin, N. G. (2003). The genetic and environmental relationship between Cloninger's dimensions of temperament and character. Personality and Individual Differences, 35, 1931–1946.Google Scholar
Goodman, R. (1997). The Strengths and Difficulties Questionnaire: A research note. Journal of Child Psychology and Psychiatry, 38, 581–586.CrossRefGoogle ScholarPubMed
Gregory, A. M., Light-Häusermann, J. H., Rijsdijk, F., & Eley, T. C. (2009). Behavioral genetic analyses of prosocial behavior in adolescents. Developmental Science, 12, 165–174.Google Scholar
Grusec, J. E. (1991). Socializing concern for others in the home. Developmental Psychology, 27, 338–342.CrossRefGoogle Scholar
Grusec, J. E., & Davidov, M. (2010). Integrating different perspectives on socialization theory and research: A domain-specific approach. Child Development, 81, 687–709.Google Scholar
Hartmann, D. P., Gelfand, D. M., Smith, C. L., Paul, S. C., Cromer, C. C., Page, B. C., et al. (1976). Factors affecting the acquisition and elimination of children's donating behavior. Journal of Experimental Child Psychology, 21, 328–338.Google Scholar
Hastings, P. D., Utendale, W. T., & Sullivan, C. (2007). The socialization of prosocial development. In Grusec, J. E. & Hastings, P. D. (Eds.), Handbook of socialization (pp. 638–664). New York: Guilford Press.Google Scholar
Hoffman, M. L. (1970). Moral development. In Mussen, P. H. (Ed.), Carmichael's manual of child development (Vol. 2, pp. 261–359), New York: Wiley.Google Scholar
Hoffman, M. L. (1988). Moral development. In Bornstein, M. & Lamb, M. (Eds.), Developmental psychology: An advanced textbook (pp. 497–548). Hillsdale, NJ: Erlbaum.Google Scholar
Hur, Y. M., & Rushton, J. P. (2007). Genetic and environmental contributions to prosocial behaviour in 2- to 9-year-old South Korean twins. Biology Letters, 3, 664–666.CrossRefGoogle ScholarPubMed
Iannotti, R. J. (1985). Naturalistic and structured assessments of prosocial behavior in preschool children: The influence of empathy and perspective taking. Developmental Psychology, 21, 46–55.CrossRefGoogle Scholar
Insel, T.R. (2003). Is social attachment an addictive disorder? Physiology & Behavior, 79, 351–357.Google Scholar
Israel, S., Lerer, E., Shalev, I., Uzefovsky, F., Reibold, M., Bachner-Melman, R., et al. (2008). Molecular genetic studies of the arginine vasopressin 1a receptor (AVPR1a) and the oxytocin receptor (OXTR) in human behavior: From autism to altruism with some notes in between. Progress in Brain Research, 170, 435–449.Google Scholar
Israel, S., Lerer, E., Shalev, I.,, Uzefovsky, F., Riebold, M., Laiba, E., et al. (2009). The oxytocin receptor (OXTR) contributes to prosocial fund allocations in the dictator game and the social value orientations task. PLoS ONE, 4, e5535.Google Scholar
Jaffee, S. R., & Price, T. S. (2007). Gene–environment correlations: A review of the evidence and implications for prevention of mental illness. Molecular Psychiatry, 12, 432–442.Google Scholar
Kan, K., Ploeger, A., Raijmakers, M. E. J., Dolan, C. V., & van der Maas, H. L. J. (2010). Nonlinear epigenetic variance: Review and simulations. Developmental Science, 13, 11–27.Google Scholar
Knafo, A. (2006). The Longitudinal Israeli Study of Twins (LIST): Children's social development as influenced by genetics, abilities, and socialization. Twin Research and Human Genetics, 9, 791–798.Google Scholar
Knafo, A., & Israel, S. (2009). Genetic and environmental influences on prosocial behavior. In Mikulincer, M. & Shaver, P. R. (Eds.), Prosocial motives, emotions, and behavior: The better angels of our nature (pp. 149–167). Washington, DC: American Psychological Association.Google Scholar
Knafo, A., Israel, S., Darvasi, A., Bachner-Melman, R., Uzefovsky, F., Cohen, L., et al. (2008). Individual differences in allocation of funds in the Dictator Game and postmortem hippocampal mRNA levels are correlated with length of the arginine vasopressin 1a receptor (AVPR1a) RS3 promoter-region repeat. Genes, Brain and Behavior, 7, 266–275.Google Scholar
Knafo, A., & Plomin, R. (2006a). Parental discipline and affection, and children's prosocial behavior: Genetic and environmental links. Journal of Personality and Social Psychology, 90, 147–164.CrossRefGoogle ScholarPubMed
Knafo, A., & Plomin, R. (2006b). Prosocial behavior from early to middle childhood: Genetic and environmental influences on stability and change. Developmental Psychology, 42, 771–786.CrossRefGoogle ScholarPubMed
Knafo, A., & Schwartz, S. H. (2003). Parenting and adolescents' accuracy in perceiving parental values. Child Development, 73, 595–611.Google Scholar
Knafo, A., Steinberg, T., & Goldner, I. (in press). Children's low affective perspective-taking ability is associated with low self-initiated prosociality. Emotion.Google Scholar
Knafo, A., & Uzefovsky, F. (in press). Variation in empathy: The interplay of genetic and environmental factors. In Legerstee, M., Haley, D. W., & Bornstein, M. H. (Eds.). The developing infant mind: Integrating biology and experience. New York: Guilford Press.Google Scholar
Knafo, A., Zahn-Waxler, C., Davidov, M., Van Hulle, C., Robinson, J., & Rhee, S. H. (2009). Empathy in early childhood: Genetic, environmental and affective contributions. Annals of the New York Academy of Sciences, 1167, 103–114.Google Scholar
Knafo, A., Zahn-Waxler, C., Van Hulle, C., Robinson, J. L., Rhee, S. H. (2008). The developmental origins of a disposition toward empathy: Genetic and environmental contributions. Emotion, 8, 737–752.CrossRefGoogle ScholarPubMed
Kochanska, G. (1995). Children's temperament, mothers' discipline, and security of attachment: Multiple pathways to emerging internalization. Child Development, 66, 597–615.Google Scholar
Krevans, J., & Gibbs, J. C. (1996). Parents' use of inductive discipline: Relations to children's empathy and prosocial behavior. Child Development, 67, 3263–3277.Google Scholar
Laucht, M., Becker, J., & Schmidt, M. H. (2006). Visual exploratory behaviour in infancy and novelty seeking in adolescence: Two developmentally specific phenotypes of ADHD. Journal of Child Psychology and Psychiatry, 47, 1143–1151.CrossRefGoogle Scholar
Locke, L. M., & Prinz, R. J. (2002). Measurement of parental discipline and nurturance. Clinical Psychology Review, 22, 895–929.Google Scholar
McClernon, F. J., Hutchison, K. E., Rose, J. E. & Kozink, R. V. (2007). DRD4 VNTR polymorphism is associated with transient fMRI-BOLD responses to smoking cues. Psychopharmacology, 194, 433–441.Google Scholar
McGowan, P. O., Sasaki, A., D'Alessio, A. C., Dymov, S., Labonté, B., Szyf, M., et al. (2009). Epigenetic regulation of the glucocorticoid receptor in human brain associates with childhood abuse. Nature Neuroscience, 12, 342–348.Google Scholar
Miller, P. A., Eisenberg, N., Fabes, R. A., Shell, R., & Gular, S. (1989). Socialization of empathic and sympathetic responding. In Eisenberg, N. (Ed.), The development of empathy and related vicarious responses: New Directions in child development (pp. 65–83). San Francisco, CA: Jossey–Bass.Google Scholar
Munafò, M. R., Yalcin, B., Willis-Owen, S. A., & Flint, J. (2008). Association of the dopamine D4 receptor (DRD4) gene and approach-related personality traits: Meta-analysis and new data. Biological Psychiatry, 63, 197–206.Google Scholar
Neale, M. C., Boker, S. M., Xie, G., & Maes, H. H. (1999). Mx: Statistical modeling (5th ed.) [Computer software]. Richmond, VA: Virginia Commonwealth University, Department of Psychiatry.Google Scholar
Oakley, B., Knafo, A., Madhavan, G., & Wilson, D. S. (Eds.). (in press). Pathological altruism. New York: Oxford University Press.Google Scholar
Oakley, B., Knafo, A., & McGrath, M. (in press). Pathological altruism—An introduction. In Oakley, B., Knafo, A., Madhavan, G., & Wilson, D. S. (Eds.), Pathological altruism. New York: Oxford University Press.CrossRefGoogle Scholar
Plomin, R. (1994). Genetics and experience: The interplay between nature and nurture. Thousand Oaks, CA: Sage.CrossRefGoogle Scholar
Plomin, R., DeFries, J. C., & Loehlin, J. C. (1977). Genotype–environment interaction and correlation in the analysis of human behavior. Psychological Bulletin, 85, 309–322.CrossRefGoogle Scholar
Plomin, R., DeFries, J. C., McClearn, G. E., & McGuffin, P. (2001). Behavioral genetics (4th ed.). New York: Worth.Google Scholar
Price, T. S., Freeman, B., Craig, I. W., Petrill, S. A., Ebersole, L., & Plomin, R. (2000). Infant zygosity can be assigned by parental report questionnaire data. Twin Research, 3, 129–133.Google Scholar
Propper, C., & Moore, G. A. (2006). The influence of parenting on infant emotionality: A multi-level psychobiological perspective. Developmental Review, 26, 427–460.Google Scholar
Robinson, C. C., Mandleco, B., Olsen, S. F., & Hart, C. H. (1995). Authoritative, authoritarian, and permissive parenting practices: Development of a new measure. Psychological Reports, 77, 819–830.Google Scholar
Rubin, K. H., Burgess, K. B., & Hastings, P. D. (2002). Stability and social–behavioral consequences of toddlers' inhibited temperament and parenting behaviors. Child Development, 73, 483–495.Google Scholar
Saudino, K. J., Plomin, R., & DeFries, J. C. (1996). Tester-rated temperament at 14, 20, and 24 months: Environmental change and genetic continuity. British Journal of Developmental Psychology, 14, 129–144.Google Scholar
Scourfield, J., John, B., Martin, N., & McGuffin, P. (2004). The development of prosocial behaviour in children and adolescents: A twin study. Journal of Child Psychology and Psychiatry, 45, 927–935.Google Scholar
Sheese, B. E., Voelker, P. M., Rothbart, M. K., & Posner, M. I. (2007). Parenting quality interacts with genetic variation in dopamine receptor D4 to influence temperament in early childhood. Development and Psychopathology, 19, 1039–1046.Google Scholar
Staub, E. (1979). Positive social behavior and morality: Socialization and development (Vol. 2). New York: Academic Press.Google Scholar
Turkheimer, E., Haley, A., Waldron, M., D'Onofrio, B., & Gottesman, I. I. (2003). Socioeconomic status modifies heritability of IQ in young children. Psychological Science, 14, 623–628.Google Scholar
Van IJzendoorn, M. H., & Bakermans-Kranenburg, M. J. (2006). DRD47-repeat polymorphism moderates the association between maternal unresolved loss or trauma and infant disorganization. Attachment & Human Development, 8, 291–307.Google Scholar
Van IJzendoorn, M. H., Bakermans-Kranenburg, M. J., Pannebaker, F., & Out, D. (2010). In defence of situational morality: Genetic, dispositional and situational determinants of children's donating to charity. Journal of Moral Education, 39, 1–20.Google Scholar
Van Lange, P. A. M. (2008). Does empathy trigger only altruistic motivation? How about selflessness or justice? Emotion, 8, 766–774.Google Scholar
Volbrecht, M. M., Lemery-Chalfant, K., Aksan, N., Zahn-Waxler, C., & Goldsmith, H. H. (2007). Examining the familial link between positive affect and empathy development in the second year. Journal of Genetic Psychology, 168, 105–129.Google Scholar
Whiteside-Mansell, L., Bradley, R., Tresch Owen, M., Randolph, S., & Cauce, A. M. (2003). Parenting and children's behavior at 36 months: Equivalence between African American and European American mother–child dyads. Parenting: Science and Practice, 3, 197–234.Google Scholar
Wise, R. A. (2004). Dopamine, learning and motivation. Nature Reviews Neuroscience, 5, 1–12.Google Scholar
Yarrow, M. R., Zahn-Waxler, C., Barrett, D., Darby J., King, R., Pickett, M., et al. (1976). Dimensions and correlates of prosocial behavior in young children. Child Development, 47, 118–125.Google Scholar
Zahn-Waxler, C., Schiro, K., Robinson, J. L., Emde, R. N., & Schmitz, S. (2001). Empathy & prosocial patterns in young MZ and DZ twins: Development and genetic and environmental influences. In Emde, R. N. & Hewitt, J. K. (Eds.), Infancy to early childhood: Genetic and environmental influences on developmental change (pp. 141–162). New York: Oxford University Press.Google Scholar
Zahn-Waxler, C., & Van Hulle, C. (in press). Empathy, guilt, and depression: When caring for others becomes costly to children. In Oakley, B., Knafo, A., Madhavan, G., & Wilson, D. S. (Eds.), Pathological altruism. New York: Oxford University Press.Google Scholar
Zarbatany, L., Hartmann, D. P., & Gelfand, D. M. (1985). Why does children's generosity increase with age: Susceptibility to experimenter influence or altruism? Child Development, 56, 746–756.Google Scholar