Birthdates play a part in sporting success

By KATHERINE HOBY

Every time Christian Cullen dives to score a try for the All Blacks, he should thank his lucky stars he was born in February.

A theory being studied in New Zealand holds that the month you were born can have a big effect on your success at sport. Children who start school early in the school year could be up to 12 months older than other children in their class who start later.

So they are bigger and more developed than others in their age bracket in sports teams and that leads to more chance of winning at sport and being successful and confident.

Dr William Low, a senior lecturer at the University of Auckland's department of management, has been studying the impact of birth month on professional rugby players.

The theory - called Relative Age Effect - was first studied in North America and figures for successful ice hockey players seem to correlate. It has also been studied among British rugby league players.

It works best for young rugby players in this country and those playing in competition to under-21 level. By the time they graduate to top-level teams (as the graphic shows) the influence of relative age has evened out.

Dr Low suggests the strong provincial competition in New Zealand might prevent early streaming of players.

Of the junior representative rugby players surveyed, 39 per cent were born in the first quarter of the year, compared with just 13 per cent in the last quarter. At senior level, birthdates were far more evenly spread, ranging from 21 to 28 per cent for each quarter.

The birthdates of Super 12 players, also, are remarkably evenly spread over the whole year.

Figures for English rugby league are most in line with the theory. They show 33.8 per cent of premier division players born in the first quarter of the sporting year, compared with with just 19.7 per cent in the last.

The study argues that the roots of achievement start when children begin playing sports at an early age.

When children start playing, they are grouped into age categories, and those who are slightly older will have the advantage, says Dr Low. "What we know is that everybody should have an equal chance of success but we end up setting up systems that work against some kids."

Older children will generally have developed more, and have better co-ordination and playing skills, even if they are older by only a few months. For rugby in this country, that means a child should be born in the first six months of the year.

"At age 6 and 7 it can make a huge difference," says Dr Low. "A child hits a certain developmental stage where running and kicking a ball makes sense, whereas it does not to a younger child. In some senses it comes back to the survival of the fittest, strongest - and oldest."

Those who are the best of their age group will often be selected for further training and have more resources poured into developing their potential. From there, it is very difficult for those not singled out to "jump the hurdle", Dr Low says.

Legendary All Blacks Colin Meads and Sean Fitzpatrick fit the theory, both being born in June. And among present players born in the first six months are Christian Cullen (February), Ben Blair (March) and Tana Umaga (May).

Some critics have argued that children who find themselves younger and smaller in class might end up having more sustained achievements through life as they strive harder to keep up with older children.

Sports psychologist and keen sports fan Jane Brown said the relative age effect was an interesting one. " Once you take a kid and give them an advantage I can see how the others would struggle to catch up."

But Ms Brown stressed there would always be players with the talent to take them all the way.