The policies that dictate the participation structure of many youth sport systems involve the use of a set selection date (e.g. 31 December), which invariably produces relative age differences between those within the selection year (e.g. 1 January to 31 December). Those born early in the selection year (e.g. January) are relatively older—by as much as 12 months minus 1 day—than those born later in the selection year (e.g. December). Research in the area of sport has identified a number of significant developmental effects associated with such relative age differences. However, a theoretical framework that describes the breadth and complexity of relative age effects (RAEs) in sport does not exist in the literature. This paper reviews and summarizes the existing literature on relative age in sport, and proposes a constraints-based developmental systems model for RAEs in sport.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Price excludes VAT (USA)
Tax calculation will be finalised during checkout.
Baker J, Horton S. A review of primary and secondary influences on sport expertise. High Ability Stud. 2004;15:211–28.
Cobley S, Baker J, Wattie N, et al. Annual age-grouping and athlete development: a meta-analytical review of relative age effects in sport. Sports Med. 2009;39(3):235–56.
Cobley S, Abraham C, Baker J. Relative age effects on physical education attainment and school sport participation. Phys Educ Sport Pedagogy. 2008;13:267–76.
Araujo D, Fonseca C, Davids K, et al. The role of ecological constraints on expertise development. Talent Devel Excellence. 2010;2:165–79.
Lerner RM. Developmental science, developmental systems, and contemporary theories of human developmental. In: Damon W, Lerner RM, editors. Handbook of child psychology: theoretical models of human development. Vol. 1. Hoboken: Wiley; 2006.
Newell KM. Constraints on the development of coordination. In: Wade MG, Whiting HTA, editors. Motor development in children: aspects of coordination and control. Amsterdam: Martin Nijhoff; 1986. p. 341–61.
Mills CW. The sociological imagination. New York: Oxford University Press; 1959. p. 66.
Coalter F. A wider social role for sport: who’s keeping score?. Abingdon: Routledge; 2007.
Baker J, Schorer J, Cobley S, et al. Circumstantial development and athletic excellence: the role of date of birth and birthplace. Eur J Sport Sci. 2009;9:329–39.
Bronfenbrenner U. Toward an experimental ecology of human-development. Am Psychol. 1977;32:513–31.
Hancock DJ, Adler AL, Cote J. A proposed theoretical model to explain relative age effects in sport. Eur J Sport Sci. 2013. doi:10.1080/17461391.2013.775352.
Cobley S, Baker J, Wattie N, et al. How pervasive are relative age effects in secondary school education? J Ed Psychol. 2009;101:520–8.
Wattie N, Cobley S, Baker J. Toward a unified understanding of relative age effects. J Sports Sci. 2008;26:1403–9.
Barnsley RH, Thompson AH, Barnsley PE. Hockey success and birthdate: the RAE. Can Assoc Health Phys Educ Recreation J. 1985;51:23–8.
Musch J, Grondin S. Unequal competition as an impediment to personal development: a review of the relative age effect in sport. Dev Rev. 2001;21:147–67.
Haywood MH, Gretchell N. Fundamental concepts. In: Life span motor development. Windsor: Human Kinetics; 2009: p. 3–15.
Phillips E, Davids K, Renshaw I, et al. Expert performance in sports and the dynamics of talent development. Sports Med. 2010;40:1–13.
Renshaw I, Davids K, Phillips E, et al. Developing talent in athletes as complex neurobiological systems. In: Baker J, Cobley S, Schorer J, editors. Talent identification and development in sport: international perspectives. London: Routledge; 2012. p. 64–80.
Malina RM, Bouchard C, Bar-Or O. Maturity-associated variation in growth and performance. In: Growth, maturation, and physical activity. Champaign: Human Kinetics; 2004.
Sherar LB, Baxter-Jones ADG, Faulkner RA, et al. Does physical maturity and birth date predict talent in male youth ice hockey players? J Sports Sci. 2007;25:879–86.
Baker J, Cobley S, Montelpare WJ, et al. Exploring proposed mechanisms of the relative age effect in Canadian minor hockey. Int J Sport Psychol. 2010;41:148–59.
Brewer J, Balsom PD, Davis J. Seasonal birth distribution amongst European soccer players. Sports Exerc Inj. 1995;1:154–7.
Romann M, Fuchslocher J. Influence of the selection level, age, and playing position on relative age effects in Swiss women’s soccer. Talent Dev Excellence. 2011;3:239–47.
Romann M, Fuchslocher J. Influences of player nationality, playing position, and height on relative age effects at women’s under-17 FIFA World Cup. J Sports Sci. 2013;31:32–40.
Weir PL, Smith KL, Paterson C, et al. Canadian women’s ice hockey: evidence of a relative age effect. Talent Dev Excellence. 2010;2:209–17.
Schorer J, Cobley S, Büsch D, et al. Influences of competition level, gender, player nationality, career stage and playing position on relative age effects. Scan J Sport Sci Med. 2009;19:720–30.
Costa AM, Marques MC, Louro H, et al. The relative age effect among elite youth competitive swimmers. Eur J Sport Sci. 2013;13:437–44.
Baker J, Schorer J, Cobley S, et al. Gender, depth of competition and relative age effects in team sports. Asian J Exer Sport Sci. 2009;6:7–14.
Hancock DJ, Starkes JL, Ste-Marie DM. The relative age effect in female gymnastics: a flip-flop phenomenon. Int J Sport Psych. In press.
Wattie N, Tietjens M, Schorer J, et al. Relative age-related participation and dropout trends in German youth sports clubs. Eur J Sport Sci. 2012;14 Suppl 1:S213–20. doi:10.1080/17461391.2012.681806.
Davison KK, Werder JL, Trost SG, et al. Why are early maturing girls less active? Links between pubertal development, psychological well-being and physical activity among girls ages 11 and 13. Social Sci Med. 2007;64:2391–404.
Sherar LB, Cumming SP, Eisenmann JC, et al. Adolescent biological maturity and physical activity: biology meets behavior. Pediatr Exerc Sci. 2010;22:332–49.
Vincent J, Glamser FD. Gender differences in the relative age effect among US Olympic development program youth soccer players. J Sport Sci. 2006;24:405–13.
Shakib S. Female basketball participation: negotiating the conflation of peer status and gender status from childhood through puberty. Am Behav Sci. 2003;46:1405–22.
Monsma EV, Malina RM. Anthropometry and somatotype of competitive female figure skaters 11–22 years: variation by competitive level and discipline. J Sport Med Phys Fit. 2005;45:491–500.
Loffing F, Schorer J, Cobley SP. Relative age effects are a developmental problem in tennis: but not necessarily when you’re left-handed! High Abil Stud. 2010;21:19–25.
Hagemann N. The advantage of being left-handed in interactive sports. Atten Percept Psychophys. 2009;71:1641–8.
Barnsley RH, Thompson AH. Birthdate and success in minor hockey: the key to the NHL? Can J Behav Sci. 1988;20:167–76.
Hancock DJ, Ste-Marie DM, Young BW. Coach selections and the relative age effect in male youth ice hockey. Res Q Exerc Sport. 2013;84:126–30.
Till K, Cobley S, Cooke C, et al. The prevalence, influential factors and mechanisms of relative age effects in UK rugby league. Scan J Med Sci Sport. 2010;20:320–9.
Daniel TE, Janssen CTL. More on the relative age effect. Can Assoc Health Phys Educ Rec J. 1987;53:21–4.
Côté J, MacDonald DJ, Baker J, et al. When ‘where’ is more important that ‘when’: birthplace and birthdate effects on the achievement of sporting expertise. J Sports Sci. 2006;24:1065–73.
Esteva S, Drobnic F. Birthdate and basketball success. FIBA Assist Mag. 2006;18:64–6.
Hoare D. Birthdate and basketball success: is there a relative age effect? In: Proceedings of the Pre-Olympic Congress: Sports Medicine and Physical Education International Congress on Sports Science. 2000 Sep 7–13; Brisbane (QLD).
Delorme N, Raspaud M. The relative age effect in young French basketball players: a study on the whole population. Scan J Med Sci Sports. 2009;19:235–42.
Dixon JC, Chittle L, Horton S. Academic timing and the relative age effect in NCAA basketball. In: Proceedings of the Canadian Society for Psychomotor Learning and Sport Psychology Conference: 2013 Oct; Kelowna (BC).
MacDonald DJ, Cheung M, Côté J, et al. Place but not date of birth influences the development and emergence of athletic talent in American football. J Appl Sport Psychol. 2009;21:80–90.
Schorer J, Wattie N, Baker J. A new dimension to relative age effects: constant year effects in German youth handball. PLoS ONE. 2013;8:e60336. doi:10.1371/journal.pone.0060336.
Wattie N, Baker J, Cobley S, et al. A historical examination of relative age effects in Canadian hockey players. Int J Sport Psychol. 2007;38:178–86.
Addona V, Yates PA. A closer look at the relative age effect in the National Hockey League. J Quant Anal Sport. 2010;6:1–17.
Cobley S, Schorer J, Baker J. Relative age effects in professional German soccer: a historical analysis. J Sports Sci. 2008;26:1531–8.
Davies G, Welham J, Chant D, et al. A systematic review and meta-analysis of Northern Hemisphere season of birth studies in schizophrenia. Schizophrenia Bull. 2003;29:587–93.
Bedard K, Dhuey E. The persistence of early childhood maturity: international evidence of long-run age effects. Q J Econ. 2006;121:1437–72.
Lerner RM, Lerner JV. Towards a new vision and vocabulary about adolescence: theoretical, empirical, and applied bases of a “positive youth development” perspective. In: Balter L, Tamis-LeMonda CS, editors. Child psychology: a handbook of contemporary issues. New York: Taylor & Francis; 2006.
Bronfenbrenner U. Making human beings human: bioecological perspectives on human development. London: Sage; 2005.
Bronfenbrenner U, Morris PA. The bioecological model of human development. In: Damon W, Lerner RM, editors. Handbook of child psychology: theoretical models of human development. Vol. 1. Hoboken: Wiley; 2006.
Davids K, Araujo D. The concept of ‘organismic asymmetry’ in sport science. J Sci Med Sport. 2010;13:633–40.
MacDonald D, Baker J. Circumstantial development: birthdate and birthplace effects on athlete development. In: Côté J, Lidor R, editors. Conditions of children’s talent development in sport. Morgantown: Fitness Information Technology; 2013: p. 197–208
Helsen WF, Starkes JL, Van Winckel J. The influence of relative age on success and dropout in male soccer players. Am J Hum Biol. 1998;10:791–8.
Lemez S, Baker J, Horton S, et al. Examining the relationship between relative age, competition level, and dropout rates in male youth ice-hockey players. Scan J Med Sci Sport. 2013. doi:10.1111/sms.12127.
Ashworth J, Heyndels B. Selection bias and peer effects in team sports: the effect of age grouping on earnings of German soccer players. J Sports Econ. 2007;8:355–77.
Baker J, Logan AJ. Developmental contexts and sporting success: birth date and birthplace effects in national hockey league draftees 2000–2005. BMJ. 2007;41:515–7.
Deaner RO, Lowen A, Cobley S. Born at the wrong time: selection bias in the NHL draft. PLoS ONE. 2013;8(2):e57753. doi:10.1371/journal.pone.0057753.
Baltes PB, Lindenburger U, Staudinger UM. Lifespan theory of developmental psychology. In: Damon W, Lerner RM, editors. Handbook of child psychology: theoretical models of human development. Vol. 1. Hoboken: Wiley; 2006.
Schorer J, Baker J, Lotz S, et al. Influence of early environmental constraints on achievement motivation in talented young handball players. Int J Sport Psychol. 2010;41:42–57.
Helsen WF, Starkes JL, Van Winckel J. Effect of change in selection year on success in male soccer players. Am J Hum Biol. 2000;12:729–35.
Musch J, Hay R. The relative age effect in soccer: cross-cultural evidence for a systematic discrimination against children born late in the competition year. Sociol Sport. 1999;16:54–64.
Rothman KJ. Causes. Am J Epidem. 1976;104:587–92.
Rothman KJ. What is causation? In: Epidemiology: an introduction. Toronto: Oxford University Press; 2002.
Schulenberg JE. Understanding the multiple contexts of adolescent risky behavior and positive development: advances and future directions. Appl Dev Sci. 2006;10:107–13.
Till K, Cobley S, O’Hara J, et al. Considering maturation status and relative age in the longitudinal evaluation of junior rugby league players. Scan J Med Sci Sport. 2013. doi:10.1111/sms.12033.
Grondin S, Deschaies P, Nault LP. Trimesters of birth and school output [in French]. Apprent Social. 1984;16:169–74.
Boucher J, Halliwell W. The Novem system: a practical solution to age grouping. Can Assoc Health Phys Educ Rec J. 1991;57:16–20.
Hurley WJ. Equitable birthdate categorization systems for organized minor sports competition. Eur J Operational Res. 2009;192:253–64.
Wattie N. Relative age effects in education and sport: an argument for human, not statistical solutions. Radical Stat. 2013;108:5–20.
Delorme N, Champely S. Relative age effect and chi-squared statistics. Int Rev Sociol Sport. 2013. doi:10.1177/1012690213493104.
Hair JF Jr, Black WC. Cluster analysis. In: Grimm LG, Yarnnold PR, editors. Reading and understanding more multivariate statistics. London: American Psychological Association; 2004.
von Eye A, Bogat GA. Person-oriented and variable-oriented research: concepts, results, and development. Merrill-Palmer Q J Devel Psych. 2006;52:390–420.
Gladwell M. Outliers: the story of success. New York: Little, Brown and Company; 2008.
Levitt S, Dubner S. SuperFreakonomics: global cooling, patriotic prostitutes, and why suicide bombers should buy life insurance. New York: William Morrow; 2009.
Support for the writing of this manuscript was provided by a doctoral fellowship from the Social Sciences and Humanities Research Council of Canada and a Sport Participation Research Initiative Supplement from Sport Canada to the first author, as well as a research grant from the Social Sciences and Humanities Research Council of Canada to the second and last authors. These funders had no role in this work and the opinions expressed represent the views of authors. Nick Wattie, Jörg Schorer and Joseph Baker have no potential conflicts of interest that are directly relevant to the content of this review.
About this article
Cite this article
Wattie, N., Schorer, J. & Baker, J. The Relative Age Effect in Sport: A Developmental Systems Model. Sports Med 45, 83–94 (2015). https://doi.org/10.1007/s40279-014-0248-9