Mar 06

The Relative Age Effect: How Does It (Dis)Advantage Young Athletes?

Share This Post!

Ever wonder if athletes possess certain advantages or drawbacks based on their birth dates? Researchers have established that this is indeed a factor and does make a difference! It becomes not only important for coaching, but also for parents to understand because of parental tendencies to compare their child/children to others within the same group.

Maybe you have heard of the Relative Age Effect (RAE) – the concept that children are placed into age groups such as school classes or sports based on chronological age. Those born early in the cohort are said to have physical or intellectual advantages compared to those born late, leading to selection for enriched opportunities that tend to compound the advantage. Research into sport shows relative age effect can be a systemic advantage to the early-born and a disadvantage to the later-born, excluding late-developers and robbing programs of talent and potential.

The existing and traditional approach by sports organizations in children and youth sports is to group athletes by chronological age, and establish the so-called ‘cut off’ date. Researchers have determined this as a shortcoming because of apparent differences between the chronological and developmental age. The chart denotes potential differences (Schloder, 2017, NCCP Lectures).

Schlots:Users:monikaschloder:Desktop:DevAge copy 2.jpg

Therefore, boys and girls within the same age group may experience certain advantages or disadvantages based on their birthdate. Does this not make competition and playing sports somewhat unfair? This imbalance is frustrating for younger athletes, leading to their early sport dropout, according to researchers in sport sociology and psychology.

I subscribe to SIRC (Sport Information Resource Centre, Ottawa) for daily emails and article links. Researchers such as Chittle, Dixon, Horton, and Baker (2018) presented their research on ‘Relative Age Effects’ (RAE) at the International Conference at York University (Toronto, Canada) on October 17, 2018. The discussion centered on athletes’ dates of birth and the potential implications on sport, education, health, and wellbeing in hopes of identifying solutions to minimize the age bias associated with using annual cut-off dates.

The following article highlights the presentation at the Conference and is somewhat modified with permission from SIRC Canada.

“Coming of Age with Relative Age Research: Origins, Consequences,

And Potential Solutions”

Within sport and educational contexts, individuals are often placed into age cohorts in an attempt to ensure fairness and equality. Yet, this process can inadvertently lead to relative age effects (RAEs), which describe the (dis)-advantages associated with being the relatively youngest or oldest within a particular age cohort (Barnsley, R.H, Thompson & Barnsley, P.B., 1985).


Let’s assume that two girls are competing for the last spot on the team roster of a youth ice hockey team. One was born in January and the other in December of the same year. Both athletes are skilled players, but because one is 11-months older (representing more than 10% additional life experience), and has had more time to develop, both cognitively and physically, coaches assess her to be the superior player, and she makes the team. Consequently, she gets additional practice time, better coaching, and the opportunity to hone her skills by competing against better teams. On the contrary, the younger one has to resign her-self to ‘playing in the local house league.’ Since this was the third season in a row that she was the last player to be ‘cut’ from the travel team, she is now contemplating quitting hockey altogether. While one’s date of birth may seem like a trivial demographic variable, the example demonstrates that its consequences can be quite profound.

Background: RAE

Interest in RAE began when Roger (R.H) and Paula Barnsley (P.B) attended a Lethbridge Broncos (formerly of the Western Hockey League in Canada) ice hockey game in 1985. As Paula was reviewing the game program, she noticed that the majority of athletes were born in the months of January, February, and March, which corresponded with the first months of the selection year based on Hockey Canada’s January 1st cut-off date. Intrigued by what she had observed, Roger went home after the game and began examining the birthdates of professional hockey players and noted the same birthdate trend, which they later coined the RAE (Barnsley et al., 1985).

Since Roger and Paula Barnsley initial discovery RAE has been examined from a variety of perspectives including sport, education, and health and wellbeing. and has garnered a great deal of attention in the popular press, having been featured in best-selling books such as Gladwell’s (2008) Outliers: The Story of Success, and Levitt and Dubner’s (2009) SuperFreakonomics; and TV programs such as 60 Minutes (CBS Interactive, 2012).

RAE in Sport

Barnsley et al presented their early findings within the context of Canadian ice hockey. These studies laid the groundwork for numerous researchers to explore the phenomenon in a variety of sports, such as soccer, baseball, rugby, and other competitive sports. Cobley, Baker, Wattie, and McKenna (2009a) illustrate that sport, particularly culturally relevant sports such as soccer in Europe and hockey in Canada are plagued with issues, especially at the regional and national levels, and foremost amongst adolescents 15-18 years. While cut-off dates precipitate relative age differences, Hancock, Adler, and Côté (2013) explain that social mechanisms such as coaches, parents, and players can perpetuate the problem of RAE. For athletes, who are relatively older and bigger than others in their age cohort, coaches may have higher expectations and provide additional training and support, which ultimately leads them to experience an accumulated advantage over time.

In some instances relatively younger athletes, who ‘survive’ biased sport systems may become more elite performers. This concept has become known as “the underdog hypothesis” (Fumarco, Gibbs, Jarvis & Rossi, 2017). However, for most relatively younger athletes, the consequences of RAEs can be stark, often resulting in negative sport experiences, which may lead to drop-out of sport altogether (Lemez, Baker, Horton, Wattie & Weir, 2014). As troubling as this outcome may be for those in the sport domain, at least youth have the opportunity to pursue other activities during their discretionary time. However, in other developmental contexts, such as education, youth do not have this option.

RAEs in Education

Let’s suppose two boys are heading to school for their first day of grade one. Both were born in January and December of 2012 respectively. This age difference in grade one may result for the younger one earning lower grades, have poorer school attendance (Cobley et al., 2009b), and be less likely to attend or complete post-secondary school (Dhuey & Figlio, 2017).

Perhaps even more disconcerting is the implication of this age disparity on health and wellbeing. Research has shown that relatively younger students demonstrate lower levels of self-esteem, are more commonly misdiagnosed with Attention Deficit Hyperactivity Disorder, have higher rates of youth suicide, and higher rates of incarceration for juvenile crimes. Borrowing ideas from the education literature, sport researchers are starting to examine the consequence of relative age on athletes’ psychosocial outcomes, including leadership, positive youth development, and developmental assets.

Proposed Solutions

While there have been a number of proposed solutions to minimize RAE (e.g., rotating cut-off dates, educating stakeholders many of these solutions have failed to garner broad support from policy makers or practitioners due to their logistical complexity. Research has demonstrated that changing cut-off dates (as prescribed for various reasons by the U.S. Soccer Federation and Little League Baseball in recent years) merely shifts who is (dis)-advantaged within an age cohort (Helsen, Hodges, Van Winckel & Starkes, 2000). Moreover, we know that education about RAE or athletes’ birthdates is insufficient in yielding behavioural change. However, interventions such as age-ordered shirt numbering may be effective at reducing coach selection bias (Mann & Van Ginneken, 2017). Similarly, corrective adjustments that account for one’s birth date in timed sporting events (e.g., sprinting) show considerable promise for mitigating RAEs, while improving broad sport participation, as well as elite athlete selection and development (Romann & Cobley, 2015).

The alternative to traditional age-based divisions is bio-banding* the process of grouping athletes on the basis of growth and maturation (*refer to p.1, chronological versus developmental age, and chart) rather than chronological age according to Cumming, Lloyd, Oliver, Eisenmann and Malina, 2017, p. 34. Bio-banding is showing positive impact by reducing injury rates and improving an individual’s ability to improve both technical and tactical skills by adjusting for their training and competitive experiences. It is one of several approaches to providing developmentally appropriate training and competition that aim to avoid the pitfalls of simple grouping based on chronological age.

Despite all of this research, more work is needed to enhance the collaboration between researchers and relevant stakeholders so that youth are not systematically (dis)-advantaged due to their date of birth. It is my belief (Schloder) that any changes have to be initiated by the respective sport organizations/federations/coaching associations to improve the approach in children and youth sports. In my sports such as swimming and athletics RAE is definitely a factor. Extensive research, however, is still lacking.

Article Authors

Laura Chittle, doctoral candidate, Department of Kinesiology at the University of Windsor: her previous work has examined the moderating impact of academic timing on relative age effect patterns within intercollegiate sport, while her current dissertation studies are evaluating the role that relative age has on athlete leadership development and positive youth experiences in sport.

Jess C. Dixon, Department of Kinesiology at the University of Windsor: his research and scholarly interests are in the areas of strategic management in sport, executive leadership and human resource management in sport, relative age effects in sport, sport finance and economics, and sport management pedagogy.

Sean Horton, Department of Kinesiology at the University of Windsor: his research interests lie primarily in the area of skill acquisition and expert performance, both in young people and as individuals age.

Joe Baker, York University: has been examining the factors affecting long-term development and performance of high performance athletes for over two decades. He currently works with several NSOs and PSOs in Canada (e.g., Wheelchair Basketball Canada, Golf Canada, Canadian Paralympic Committee, Canadian Sport Institute Ontario) to improve models of athlete development and the delivery of evidence-based approaches to skill acquisition.


SIRCuit, February 14, 2019. Email to Schloder.


Barnsley, R.H, Thompson, A.H., & Barnsley, P.B. (1985). Hockey success and birthdate: The Relative age effect. Journal of the Canadian Association of Health, Physical Education and Recreation, Vol. 51. Key: citeulike:9673950 and www.citeulike.org/group/15540/article/9673950

Chittle, L., Dixon, J.C., Horton, S., & Weir, P. (2018). Exploring the relationship between the relative age effect and youth development among male recreational ice hockey players. Journal of Amateur Sports (JAS).

Cobley, S., Baker, J., Wattie, N., & McKenna, J. (2009a). Annual age-grouping and athlete development: a meta-analytical review of relative age effects in sport. Sports Medicine, 39(3): 235-256. doi: 10.2165/00007256-200939030-00005.

Cobley, S., Baker, J., Wattie, N., & McKenna, J. (2009b). How pervasive are relative age effects in secondary school education. Journal of Educational Psychology, 101(2), 520-528.

Cobley, S., Baker, J., Wattie, N., & Montelpare, W. (2009b). A historical examination of relative age effects in Canadian hockey players. International Journal of Sport Psychology 38(2),178-186.

Costa, A.M., Marques, M.C., Louro, H., Ferreira, S.S., & Marinho, D.A. (2013). The relative age effect among elite youth competitive swimmers. European Journal of Sport Science, 13(5), 437-444. doi: 10.1080/17461391.2012.742571. Epub 2012 Nov 13. https://www.ncbi.nlm.nih.gov/pubmed/24050459

Cumming, S.P., Lloyd, R.S., Oliver, J.L., Eisenmann, J.C., & Malina, R.M. (2017). Bio-banding in sport: Applications to competition, talent identification, and strength and conditioning of youth athletes. Strength & Conditioning Journal, 39(2), 34-47.

Dhuey, E., Figlio, D., Karbownik, K., & Roth, J. (2017). School starting age and cognitive development. Institute for Northwestern Policy Research. Working Papers. WP-17-16.


Fumarco, L., Gibbs, B.G., Jarvis, J.A., & Rossi, G. (2017). The relative age effect reversal among the national hockey league elite. https://doi.org/10.1371/journal.pone.0182827 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0182827

Hancock, D.J., Adler, A.L., & Côté, J. (2013). A proposed theoretical model to explain relative age effects in sport. European Journal of Sport Science, 13(6), 630-637.

Harper, V., & Jurbala, P. (2018). Bio-banding and developmental age. SIRC Blog. January 31, 2018. https://sirc.ca/blog/brief-bio-banding-and-developmental-age

Helsen, W.F., Hodges, N.J., VAN Winckel, J., & Starkes, J.L. (2000). The roles of talent, physical precocity and practice in the development of soccer expertise. Journal of Sports Sciences,18, 727-736.

Jurbala, P. (2018). What’s the latest on relative age effects? Director, Knowledge, Sport for Life Society. http://sportforlife.ca/whats-the-latest-on-relative-age-effects/


Lemez, S., Baker, J., Horton, S., Wattie, N., & Weir, P. (2014). Examining the relationship between relative age, competition level, and dropout rates in male youth ice-hockey players. Scandinavian Journal of Medical Science in Sports, 24(6), 935-942. doi: 10.1111/sms.12127. Epub 2013 Sep 30.


Mann, D.L., & Van Ginneken, P. (2017). Age-ordered shirt numbering reduces the selection bias associated with the relative age effect. Motor learning & Performance IBBA, Amsterdam Movement Sciences – Sports and Work.

Romann, M., & Cobley, S. (2015). Relative age effects in athletic sprinting and corrective adjustments as a solution for their removal. https://doi.org/10.1371/journal.pone.0122988

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>