Soccer is a game that in many parts of the world is taken rather seriously. Perhaps we see the most intense emotional reactions in fans of this game, compared to any other, after their team wins or loses. An unexpected win or loss means that this reaction endures. But for how long?
Several newspapers have long conjectured a connection between unexpected “shock” events in sports, and fertility – the number of babies born approximately 9 months after the event. In February 2010, nine months after Andrés Iniesta of FC Barcelona scored a last minute (game-winning) goal against Chelsea FC in the UEFA Champions League semi finals, newspapers reported a 45% increase in child births in Catalonia. In a study that substantiated this fabled connection, Jesus Montesinos et al. found a 16 % increase (far from 45%, but still significant) in births.
“newspapers reported an increase in the number of births in Iceland nine months after the country unexpectedly beat England in the 2016 UEFA Europe Cup; in Germany in 2007 after its initially successful performance in the FIFA 2006 World Cup; and in England in 2003 after it reached the quarter-finals of FIFA World Cup in 2002”
Although a causal relationship between events in sports and fertility has not been established, it is speculated that heightened euphoria caused by unexpected victories can result in “celebratory intercourse.” There is some evidence that winning or losing in elections or sports can lead to hormonal fluctuations (Bernardi, 2021). This results in increased libido following wins and decreased libido following losses, not only for contestants, but also emotionally invested supporters and fans.
“This single goal (Iniesta, 2009) was so emotive that the skies over Catalonia reverberated with fireworks, shouts of joy, and the banging of pots and pans. According to some media reports, many fans also celebrated by making other kinds of noises”
In a recent study, Fabrizio Bernardi and Marco Cozzani looked at whether unexpected results to local soccer games affected fertility in Spain (Spaniards take soccer very seriously). They obtained data from the internet on betting odds of every game of the Spanish major soccer league (la Liga, season 2000/2001 to season 2014/2015) and compared them against actual outcomes. This helps determine which of the games were “shock” events – unexpected wins or unexpected losses as opposed to expected wins/losses.
“It is not the simple level of gain or loss that drives individual mood, but the level compared to prior expectations of the outcome.”
They calculated the number of predicted and unpredicted wins/losses of favorite teams for each province in Spain, and examined correlations with monthly counts of births. Researchers found that one unexpected loss by the local team (“a defeat when the most popular team in the province was predicted to win with a probability >0.66”) led to a 0.8% decrease in the number of birth nine months later. However, they found no spike in births due to unexpected wins.
The researchers think that ‘loss aversion’ (Kahneman and Tversky 1979), the unequal effect of loss on human psyche compared to a win of similar magnitude, might account for the disparity. This means that unexpected losses were more likely to cause “sorrowful abstention” (which was detectable) than unexpected wins were to cause “celebratory Intercourse” (which was not).
Read more about the study here.
