That sport can produce stories which are truly heartwarming is hardly news, but in the past week, a story emerged from New Jersey in America that is not merely feel-good, it also provides a lesson which should be taken on board by everyone involved in sport.

A week ago, St John’s 5th grade basketball team were due to play against a team from St Bartholomew the Apostle, but there was a hitch. The squad from St John’s consisted of eleven 10 year-olds – nine boys and two girls.

With just two games of the season to go though, St John’s were told that they should never have played as a co-ed team and they were given an ultimatum; continue without the girls or else forfeit the entire season.

St John’s coach, Rob Martel, deemed the decision too important for him to make so gave the team the authority to decide the course of action they wanted to take. A show of hands was asked for; did the team want to play the rest of the season without the girls or did they want to stick together as a team as they had all year?

They were warned that if the girls were not kicked out, St John’s would be disqualified and their chance to make the play-offs would be lost. Nevertheless, the decision was unanimous – the team wanted to stick together.

Dumping the girls wasn’t an option. A chant of “unity” was started by one of the boys. The reaction of the parents was of extreme pride: “These kids are doing the right thing – we don’t have to tell them what to do, they just know. It’s amazing,” said one parent before coach Martel added: “This is adults that couldn't figure out how to let the kids play two more games. This isn't the WNBA or NBA. The kids are just trying to get better, and I think they got better today."

Yes, this is a sweet story but it’s more than that. This proves a bigger point about sexism in sport and how prejudice is not inevitable. In modern-day sport, the general feeling is that women’s sport and female athletes are inferior to their male counterparts.

The common reason cited by men for not watching women’s sport is that it is not as high quality as the men’s version that they are so used to watching. How much of this is learned behaviour, though? The story of St John’s 5th grade basketball team suggests that much of the sexism, if not all of it, is learned through the kids' environment rather than a conclusion that they have arrived at independently.

The 10 year-old boys in St John’s basketball team had no reason to believe that the girls on their team were inferior, so therefore excluding them from their team did not cross their minds.

It is likely that unless any 10 year-old has been told differently, they will have a similar mindset. Both boys and girls have the ability to be equally competitive, driven, committed and skilful and, before children reach their teenage years, there is often little difference in their physical abilities. As boys and girls grow older, a gap in physical ability emerges but in all other areas, male and female athletes remain on an equal footing.

So where does this apathy from men towards women’s sport that invariably appears later in life come from? It comes from both boys and girls being told time and time again that girls are not good at sport.

As highlighted in the #LikeAGirl advertising campaign by Always, the statements “you run like a girl” or “you throw like a girl” or “you kick like a girl” are used as an insult. When told to run like a girl, very young girls believe that means run as fast as you can. But as soon as they hit 10 or 11 years of age, they start to believe it means running in a pathetic, girly way.

This is a belief that is also drilled into boys as they grow older – you don’t want girls in your team because they’re not as good. In primary schools, sport can often be segregated but does this not encourage the latent sexism that becomes all too present in later life?

Sexism does not develop innately so if boys coexist on the sports field with girls and do not have it drilled into them that girls are substandard, is there not a good chance that by the time this generation reaches adulthood, they will not believe quite as resolutely that women’s sport is inferior as many men do these days?

Women’s sport has many challenges but by continually belittling it and demeaning female athletes, a prejudice is created which is utterly preventable. As the #LikeAGirl campaign highlights, why can’t "run like a girl" also mean "win the race?" Until young boys are told differently, they believe that running like a girl can absolutely mean finishing first. So let’s stop telling them differently.