While supervision has been widely explored across therapeutic modalities, there remains a significant gap in understanding how to supervise clinicians working with family constellations that include identical twins. This qualitative case study addresses this gap by examining how systemic supervisors conceptualize and support therapists treating families with identical twins, a population that presents unique relational, developmental, and identity-based challenges. Using a semistructured vignette, five licensed marriage and family therapy supervisors were interviewed to explore their clinical reasoning, supervisory strategies, and systemic considerations. Thematic analysis revealed three core themes: identity development, role differentiation, and systemic conceptualization, each embedded within cultural and contextual family dynamics. Supervisors emphasized the importance of individualized assessment, cultural humility, and fostering differentiation not only between twins but within the family system as a whole. Findings informed the development of a practical Matrix Checklist for use in both supervision and treatment. This case study offers one of the first frameworks specifically designed to address the therapeutic and supervisory complexities of working with identical twin family systems.
AinslieR. (1997). The psychology of twinship. Jason Aronson Inc.
2.
AllenJ.AllenN.MooreJ. (2020). Articulating twintimacy as a communicative and cultural perspective on twinships. Journal of Family Communication, 20(1), 51–65. https://doi.org/10.1080/15267431.2019.1659272
BaconK. (2006). ‘It's Good to be Different': Parent and child negotiations of ‘twin’ identity. Twin Research and Human Genetics, 9(1), 141–147. https://doi.org/10.1375/twin.9.1.141
5.
BaconK. (2019). 5 Contexts of twinship: Discourses and generation. In FrankelS.McNameeS. (Eds.), Contextualizing childhoods: Growing up in Europe and North America (pp. 107–128). Macmillan.
6.
BostockL.PatrizioL.GodfreyT.ForresterD. (2022). Why does systemic supervision support practitioners’ practice more effectively with children and families?Children and Youth Services Review, 142, 106652. https://doi.org/10.1016/j.childyouth.2022.106652
BowenM. (1974). Toward the differentiation of self in one's family of origin. In Georgetown family symposium (Vol. 1, pp. 00–00). Department of Psychiatry, Georgetown University Medical Center.
9.
BurlinghamD. (1952). Twins: A study of three pairs of identical twins. International Universities Press.
ClarkP. M.DickmanZ. (1984). Features of interaction in infant twins. Acta Geneticae Medicae et Gemellologiae, 33(2), 165–171. https://doi.org/10.1017/s0001566000007194
12.
CreswellJ. W.PothC. N. (2018). Qualitative inquiry and research design: Choosing among five approaches fourth edition. Sage Publications, Inc.
13.
EmdeR. N. (1994). Individuality, context, and the search for meaning. Child Development, 65(3), 719–737. https://doi.org/10.2307/1131414
14.
ErbeliF.RiceM.ParacchiniS. (2022). Insights into dyslexia genetics research from the last two decades. Brain Sciences, 12(1), 27. https://doi.org/10.3390/brainsci12010027
15.
FreitasG. J. (2002). The impact of psychotherapy supervision on client outcome: A critical examination of 2 decades of research. Psychotherapy: Theory, Research, Practice, Training, 39(4), 354–367. https://doi.org/10.1037/0033-3204.39.4.354
16.
GottfriedN. W.SeayB. M.LeakeE. (1994). Attachment relationships in infant twins: The effect of co-twin presence during separation from mother. The Journal of Genetic Psychology, 155(3), 273–281. https://doi.org/10.1080/00221325.1994.9914777
17.
HagedornJ. W.KizziarJ. W. (1974). Gemini: The psychology and phenomena of twins. Droke House/Hallux.
18.
HarrisJ. R. (2006). No two alike: Human nature and human individuality. W W Norton & Co.
19.
JinH.HanY.ZenkerJ. (2024). Cellular mechanisms of monozygotic twinning: Clues from assisted reproduction. Human Reproduction Update, 30(6), dmae022. https://doi.org/10.1093/humupd/dmae022
20.
KanterJ. R.BouletS. L.KawwassJ. F.JamiesonD. J.KissinD. M. (2015). Trends and correlates of monozygotic twinning after single embryo transfer. Obstetrics and Gynecology, 125(1), 111–117. https://doi.org/10.1097/AOG.0000000000000579
21.
KleinB. (2012). Alone in the mirror: Twins in therapy. Routledge/Taylor & Francis Group.
22.
KleinB. S. (2003). Not all twins are alike. Praeger Publishers.
23.
KostK.ZolnaM.MurroR. (2023). Pregnancies in the United States by desire for pregnancy: Estimates for 2009, 2011, 2013, and 2015. Demography, 60(3), 837–863. https://doi.org/10.1215/00703370-10690005
Le GrangeD.SchwartzS. (2003). Family therapy for identical twins with anorexia nervosa. Eating and Weight Disorders-Studies on Anorexia, Bulimia and Obesity, 8, 84–87. https://doi.org/10.1007/BF03324995
26.
LiddleH. A. (2014). Training and supervision in family therapy: A comprehensive and critical analysis. In Handbook of family therapy (pp. 638–697). Routledge.
MaslowA. H. (1968). Toward a psychology of being (2nd ed.). Van Nostrand Reinhold.
30.
MaslowA. H. (1970). Motivation and personality (2nd ed.). Harper and Row.
31.
MaxonB.DanielsD. N. (2008). Personality differentiation of identical twins reared together. Enneagram Journal, 1(1), 65–76.
32.
MilesM. B.HubermanM.SaldañaJ. (2020). Qualitative data analysis: A methods sourcebook. Sage Publications, Inc.
33.
MinuchinS.NicholsM. P. (1998). Structural family therapy. In DattilioF. M. (Ed.), Case studies in couple and family therapy: Systemic and cognitive perspectives (pp. 108–131). Guilford Press.
NobleN.BradleyL. (2021). Becoming an individual: Promoting twins’ identity development through counseling techniques. Journal of Creativity in Mental Health, 16(3), 337–347. https://doi.org/10.1080/15401383.2020.1789015
36.
NobleN.BradleyL.ParrG.DuemerL. (2017). Fostering twins’ identity development: A family issue. The Family Journal, 25(4), 345–350. https://doi.org/10.1177/1066480717731239
37.
ParkH. R. P.ChilverM. R.QuidéY.MontaltoA.SchofieldP. R.WilliamsL. M.GattJ. M. (2024). Heritability of cognitive and emotion processing during functional MRI in a twin sample. Human Brain Mapping, 45(1), e26557. https://doi.org/10.1002/hbm.26557
PietiläS.BjörklundA.BülowP. (2013). ‘We are not as alike, as you think’ sense of individuality within the co-twin relationship along the life course. Journal of Aging Studies, 27(4), 339–346. https://doi.org/10.1016/j.jaging.2013.08.001
PogrebinA. (2010). One and the same: My life as an identical twin and what I’ve learned about everyone’s struggle to be singular. Anchor.
42.
PrescottC. A.KendlerK. S. (1995). Twin study design. Alcohol Health and Research World, 19(3), 200–205.
43.
PrestL. A.ProtinskyH. (1993). Family systems theory: A unifying framework for codependence. The American Journal of Family Therapy, 21(4), 352–360. https://doi.org/10.1080/01926189308251005
44.
SahuM.PrasunaJ. G. (2016). Twin studies: A unique epidemiological tool. Indian Journal of Community Medicine : Official Publication of Indian Association of Preventive & Social Medicine, 41(3), 177–182. https://doi.org/10.4103/0970-0218.183593
45.
SaldañaJ. (2021). The coding manual for qualitative researchers (4th ed.). Sage Publications. Chapter 1: An Introduction to Codes and Coding.
46.
SandbankA. C. (1999). Personality, identity and family relationships. In SandbankA. C. (Ed.), Twin and triplet psychology: A professional guide to working with multiples (pp. 167–185). Taylor & Frances/Routledge.
47.
SchaveB.CirielloJ. (1983). Identity and intimacy in twins. Praeger.
48.
ScheinfeldA. (1976). Twins and supertwins. J. B. Lippincott Company.
49.
SpencerR.PryceJ. M.WalshJ. (2014). Philosophical approaches to qualitative research. In LeavyP. (Ed.), The Oxford handbook of qualitative research (pp. 81–98). Oxford University Press.
von BertalanffyL. (1968). General system theory: Foundation, development, application. Braziller.
56.
WatzlawickP.BeavinJ. H.JacksonD. D. (1967). Pragmatics of human communication: A study of interactional patterns, pathologies, and paradoxes. W. W. Norton.
WilliamsP. T.BlancheP. J.RawlingsR.KraussR. M. (2005). Concordant lipoprotein and weight responses to dietary fat change in identical twins with divergent exercise levels 1. The American Journal of Clinical Nutrition, 82(1), 181–187. https://doi.org/10.1093/ajcn.82.1.181
59.
WilsonK.BarronC.WheelerR.JedrzejekP. E. A. (2018). The importance of examining diversity in reflective supervision when working with young children and their families. Reflective Practice, 19(5), 653–665. https://doi.org/10.1080/14623943.2018.1538956
60.
ZhangH.WatkinsC. E.Jr.HookJ. N.HodgeA. S.DavisC. W.NortonJ.WilcoxM. M.DavisD. E.DeBlaereC.OwenJ. (2022). Cultural humility in psychotherapy and clinical supervision: A research review. Counselling & Psychotherapy Research, 22(3), 548–557. https://doi.org/10.1002/capr.12481
