The aim of this study is to test the presence of the relative age effect (RAE) and to examine height in an overall population of the young French basketball players from 7 to 18 years old, male (n=151 259) and female (n=107 101). For the boys as for the girls, the results show a statistically significant RAE in all age categories. The effect seems more pronounced during puberty. As far as the height is concerned, players born during quarters 1 and 2 are always significantly taller than those born during quarter 4, apart from the 17-year-old female players. These results require a new look at the methodology in the statistical calculation and the interpretation of RAE. A study wanting to give a precise measurement of this effect will have to take as the expected theoretical distribution the whole population of licensed players in the corresponding years, rather than one on the global population of the country. This will avoid the hasty conclusion that an asymmetric distribution of dates of birth of professional players would be due to RAE, whereas in reality it would be representative of one existing in the population of licensed players.

The aim of the current research was to investigate the relative age effect (RAE) as a factor of basketball dropout. In order to do so, we examined the distribution of birth dates of young male (n=44,498) and female (n=30,147) French basketball players who have dropped out this sport during or at the end of the 2005-2006 season. χ(2) analyses showed an underrepresentation of dropouts among male players born early in the competition year and an overrepresentation among those born late in the "9-10 years old,""11-12 years old," and "13-14 years old" categories and in the first year of the "15-17 years old" category. Concerning girls, this asymmetry was observed across the same age categories. For both boys and girls, there was no biased distribution in the "7-8 years old" category. Findings of the present study confirm that the RAE should be taken into consideration in studies about sport dropout as a variable that may influence this phenomenon significantly.

The aim of this study was to examine the birthdates distribution of French male soccer players (n = 363,590) who dropped out during or after the 2006-2007 season, to test whether the Relative Age Effect (RAE) is linked to the dropout behaviour. An over-representation of players born late in the competitive year was found among dropouts, from the U9 to the U18 age categories, whereas their counterparts born earlier in the year were under-represented.The distortion of the distribution was particularly important for the extreme quarters of the competitive year, and in the U13 and U15 categories. This biased distribution was however not confirmed regarding the U7 category. Finally, regarding the adult category, an unbiased distribution of dropouts was found as hypothesized. Practical implications to avoid the negative consequences of RAE are advanced.-3 -

Sport sciences researchers talk about a relative age effect when they observe a biased distribution of elite athletes' birthdates, with an over-representation of those born at the beginning of the competitive year and an under-representation of those born at the end. Using the whole sample of the French male licensed soccer players (n = 1,831,524), our study suggests that there could be an important bias in the statistical test of this effect. This bias could in turn lead to falsely conclude to a systemic discrimination in the recruitment of professional players. Our findings question the accuracy of past results concerning the existence of this effect at the elite level.

The relative age effect (RAE) is a biased distribution of elite athletes' birthdates, with an overrepresentation of those born at the beginning of the competitive year and an underrepresentation of those born at the end. Despite an abundant literature, the impact of sex on this phenomenon remains neglected by most researchers. This study investigated the whole sample of female soccer players affiliated to the French Soccer Federation for the 2006-2007 season (n=57 892). It first aimed at testing the presence of RAE depending on age. Next, we looked at the birthdates of dropout players during the next season (n=15 285), to test whether relative age accounts for dropout from the activity. The analyses revealed significant differences between the expected and the observed distributions for all age categories. Furthermore, a significantly biased distribution of dropout players' birthdates was found for the <10, <14, and <17 categories. On the whole, dropout players are underrepresented in Q1 and Q2, but overrepresented in Q3 and Q4. This study completes the literature on RAE among females, but the inconsistency of the results calls for more research on this population.

The aims of this study were to test for the presence of a relative age effect among male (n = 119,715) and female (n = 12,823) members of the shooting sports federation, and to determine whether any such effect has an impact on dropout from the sport. For the boys and girls, the results show a uniform distribution of dropout. A relative age effect was not found for the girls, showing that in female shooting sports there is no such effect. For the males, a significant statistical relative age effect was not detected in the 18-20 and 13-14 year categories. However, a relative age effect was found among adults and the 11-12 and under 11 year categories. A significant "inverse" relative age effect was found for the 15-17 year group. Further qualitative research is needed to clarify which factors contribute to this asymmetric distribution of birth dates in French male shooting sports.

The relative age effect (RAE) is considered a common phenomenon in elite sport. Howeven it has not been examined systematically in previous research, and the mechanisms likely to generate or to limit such an effect are little understood. This paper investigates the prevalence of the RAE in French professional championship-level players, taking into account the potential influence of gender. Among all investigated sports, no statistically significant RAE was found, except for male ice hockey. For male handball and rugby union a trend was detected, but the RAE did not appear statistically significant. In line with previous'studies, n osignificant RAEs were found in female elite sports. The results are discussed with regard to the potential mechanisms underlying RAE.

Previous research suggested that the relative age effect (RAE) has a psychological influence on children and their decision to engage in a particular sport. Relatively younger children seem to have lower self-esteem. Indeed, because of the disadvantages of being younger, it is assumed that these players experience more situations of failure and inferiority. Because of these negative performance cues, it is likely that these young players feel less competent, which eventually leads to a higher dropout rate. These children can also decide to participate in sports in which physical attributes are less important. This shift from one sport to another can be interpreted as a 'strategic adaptation'. The purpose of this study was thus to investigate whether refereeing could be another form of 'strategic adaptation'. If a child chooses a specific sport but then does not feel competent enough to be a player, refereeing might be an alternate path followed to stay in the environment of a sport they like. Given the minimal age limits for refereeing, two hypotheses were formulated: (1) 'reversed' RAE would be observed in district referees younger than 18 years old and (2) no RAE would be observed in district referees older than 18 years old, regional referees and national referees. The birthdates of all official male soccer referees (n=13,952) were collected from the federation database. Results show that the distribution of all district referees was significantly unbalanced (χ(2)=18.73, df=3, P<0.001) with an over-representation of individuals who were born in the second half of the competitive year. As expected, this imbalance was exclusively located in district referees of 18 years old and less (χ(2)=8.03, df=3, P<0.05), while the distribution was uniform for adults (χ(2)=5.17, df=3, P<0.16). Concerning regional referees (χ(2)=2.09, df=3, P<0.554) and national referees (χ(2)=3.75, df=3, P<0.290), the results also provide support for our initial hypothesis as uniform distributions were found for both groups. This study brings to light new elements in the potential relationship between relative age and refereeing. Qualitative and/or longitudinal research is needed to confirm our quantitative data.