Why should talent identification take into consideration the effects of individual differences?
David Kip, 2010
For years, the very talented Swedish football player Zlatan Ibrahimovic has complained in Swedish media about The Swedish Football Association not giving young talented football players the opportunity to play in the national team. He thinks they should be given the opportunity earlier in their careers so they can develop faster as football players. He also thinks they should be given the opportunity to play in the big leagues of Europe earlier than often is done today. By holding them back, he thinks The Swedish Football Association in this way inhibits strong regeneration within Swedish football, mainly The National Team. He also claims the procedure of selecting talented young players is more sophisticated and effective in other countries such as Spain.
Tomas Peterson (2004), Swedish professor in sport science revealed in his study of selection procedure in Swedish football a phenomenon called "The Relative Age Effect". His report showed that selections of youth talent are based on when young boys and girls were born, rather than on talent (Peterson, 2004). This phenomenon is shown to be a consequence of coaches selecting their best players for competition and training camps already from 7 to 8 years-of-age (Peterson, 2004). The hypothesis are that greater maturation rather than individual potential are seen as "talent", and as a result children born earlier in the selection year is more likely to be selected to higher calibre teams (Wettie et al, 2004). The phenomenon is not solely a phenomenon within Swedish football, it is also a well-documented phenomenon all over the globe (Helsen et al, 2004), and maybe the real reason for loss of talent within Swedish football regeneration programme.
The Relative Age Effect
In most countries children in youth sport competitions are generally grouped by chronological age (e.g. under-15 (U15), U16, U17 and U18), the selection year often equal to the "academic year", between 1 January and 31 December (Helsen et al, 2004). Research by Helsen et al, (2004) on European football have shown that children born early in the year are more likely to be identified as talented by their coaches, and to become involved in the sport as a professional. This is coherent by studies in Sweden (Peterson, 2004), Spain (Jiménez and Pain, 2008) and Germany (Cobley et al, 2008). They all point out that "the relative age effect" is a well-documented phenomenon all over the globe, and is not solely a phenomenon within football. Peterson (2004) found the same phenomena in Swedish ice hockey, and both studies by Stephen et al (2008) and Jiménez and Pain (2008) refers to studies in Canadian ice hockey, volleyball teams, all codes of rugby and netball.
The start of the selection year is a more important factor to "the relative age effect" than time of birth within the year. In Belgium the start of the selection year was shifted from 1 August to 1 January 1997, and a comparison made by Helsen et al (2000) showed that previous to the shift players born in October to December was more likely to be selected, but after the shift players born in January to May were more likely to be selected. This relationship is why scientist can compare data between different sports, and different countries regardless of the time of season (Wettie et al, 2008).
In explaining "the relative age effect", it has usually been suggested that relatively older children are more advantaged due to greater physical maturity (Helsen et al, 2000 and Wettie et al, 2008). The hypothesis are that greater maturation rather than individual potential is equated with "talent", and as a result children born earlier in the selection year is more likely to be selected to higher calibre teams, and to be selected to play in sport events such as "Under 7s football" in England (Wettie et al, 2008), and the ice-hockey event TV-puck in Sweden (Peterson, 2004). According to Malina et al (2004), biological maturity status has been associated with slightly higher performance on sport specific football skills in adolescents (13-15 year-of-age), but there was no high statistical significance. There was, however, a bigger difference in functional capacity, specifically running speed and explosive power (Malina et al, 2004). Malina et al (2004) point out that "skill is more difficult to measure than physiological indicators such as speed and power", and maybe this statement really shows the difficulty of measuring "talent". Perhaps the selection of "talented" players also in the early years of development is more likely to be based on body size, speed and power, rather than sport specific skills. It is however suggested that psychosocial maturity plays an important roll as well (Helsen et al., 2000). This could be cognitive skills, dribbling combined with passing or shooting, and the ability to "read the game". These abilities could of course also be maturity-associated, but are difficult to measure. Maybe physiological maturity is of more importance in pre-puberty children than post-puberty adolescents, in which maturity-associated variation is less likely to be shown (Malina et al., 2004). There seem though to be a lack of good studies in sport specific skills among youth players. One problem could be the difficulty of comparing trained players recognising the tasks with novices, or that late-developers are more likely to drop-out of sports all together and therefore are not available for comparison.
Looking at gender differences highlight the importance of individual differences and further shows that "the relative age effect" really can be due to maturity status more than potential. Peterson (2004) did a brief comparison between the genders and claims that "the relative age effect" occurs among female players as well as male players. A closer look to the data rather reveals that the effect is not as significant as with male players. This is coherent with a study by Vincent and Glamser (2005) in which they compared "the relative age effect" between the genders among US Olympic Development Program (ODP). In their study Vincent and Glamser (2005) showed no significant difference among the female players born 1983-1985 (within each age group), whilst there was a "relative age effect" among their male peers. They discuss two interesting suggestions for this phenomenon; (1) females mature faster and develop more quickly, so when selection is taking place in the years of adolescents the differences between early-developers and late-developers are not as big as with their male peers; and (2) when females go through puberty they don't develop in the same manner. Whilst male grow and develop more strength and power (muscle mass), females develop more body fat, and a body constellation with wider hips and shorter legs, which is not an advantage for football performance. This means that puberty can inhibit football skill development among females, compared to enhancing football skill development among males. Thus, female early-developers can actually be disadvantaged during these years, which is usually between 11 and 14 years-of-age (Vincent and Glamser, 2005). There is still a small "relative age effect" among female players, but perhaps the advantages the early-developers have during the early years before puberty makes up for the disadvantages during puberty. Among male players, puberty instead increases "the relative age effect" as shown by e.g. Peterson (2004).
Children born late in the year are more likely to drop out of the sport as early as 12 years-of-age. This is probably due to selection-programmes of talented players, which already begin in the 6 to 8-year-old age group (Helsen et al., 2000, Helsen et al., 2004 and Peterson, 2004). The reason for these dropouts is suggested to be low self-esteem by not being selected, and to be forced to play with more mature children (Helsen et al, 2000). Most of the dropout occur within or around the age of puberty (Helsen et al, 2000), and this can perhaps be explained with the differences of body constellation between early- and late-developers during puberty. It should also be kept in mind that children within this age group would be more likely to develop other interests. If someone has been neglected up until this point, that person will naturally begin with other activities. This point of view has not been fully considered within the studies about "the relative age effect" among male players - although Peterson (2004) discusses similar thoughts - but is considered in the study of gender differences by Vincent and Glamser (2005).
Late-developers that do not drop out, but rather continue with their sport seem more likely to be successful than early-developers. Harder training, more focus, and stronger psychic due to constant struggle of keeping up with the more mature peers, could be the reason for this (Peterson, 2004). If this is true, than Peterson (2004) has a good point when he suggest that talent should be considered to be more than just about motor skill, it should also be about commitment, motivation, and interest.
A coach working within youth sport ought to be aware about individual differences in maturity, and what impact this has on development of motor skills. To avoid "the relative age effect" and dropouts in sport, a coach should notice individual development as potential, rather than comparing peers with each other. With a wider view of what talent is coaches should be able to spot more talent and work for a stronger regeneration in football as well as other sports, and give more young players with talent time to develop their skills. So maybe holding them back a little bit is not such a bad thing after all. It will give players the chance of develop event further and better chance of being selected for higher calibre teams, just like Zlatan Ibrahimovic so desperately requests.
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