Well, now we know exactly why – on a chemical level – boys will be boys when a ballgame hangs in the balance. According to a study published Wednesday, dudes actually become even more dude-like while watching their beloved teams compete.

Blame steroids. The natural kinds, that is. During games, two hormones – testosterone and cortisol – increase within the bodies of sports boosters, especially “dedicated, young, male fans,” writes a study team headed by Leander van der Meij, a PhD at the University of Valencia in Spain and VU University Amsterdam in the Netherlands…

The scientists examined 50 Spanish soccer fans (via 5-milliliter saliva samples) as the group viewed the 2010 World Cup finals between Spain and the Netherlands. (Spain won 1-0). Interestingly, “no sex differences” were noted in the testosterone levels of the fans examined, said van der Meij.