Can you tell just by the photos which team is more likely to win? For instance, if the players are smiling, does that indicate self-confidence and a higher likelihood of victory? If they're striking a more angry facial expression, does that demonstrate strength and determination?
In a new paper published in the Journal of Economic Psychology (ungated earlier version here), Astrid Hopfensitz (University of Toulouse Capitole) and Cesar Mantilla (Universidad del Rosario, Colombia) looked at data from player photos (from the Panini stickers collections) for every world cup from 1970 to 2014. First, they identified using automated software (FaceReader):
...the activation level of six basic emotions: anger, happiness, disgust, fear, sadness, and surprise, which are non-exclusive.They then tested whether those emotions (averaged at the team level, rather than individually) were associated with team success in the World Cup, for the 304 teams that took part in those tournaments. They found that:
...display of anger as well as happiness is positively correlated with a favorable goal difference (i.e. more goals scored than conceded). This correlation is robust to the inclusion of our control variables... We also observe the standardized display of anger and happiness is negatively correlated with the overall ranking in the World Cup... That is, teams that display either more anger or happiness, reach an overall better position in the whole tournament...
We observe a clear difference with respect to the two emotions. While the display of happiness is linked to the scoring of goals... anger is linked to conceding fewer goals...Interesting, when they separate the analyses for defensive and offensive players, they find that:
...the display of happiness is still predictive in each sub-group. By contrast, the display of anger remains predictive only for defensive players, and for one of the outcomes.Teams with happy offensive players do well, and teams with happy (or to a lesser extent, angry) defensive players do well.
Now, I know you're scrolling back up to check the France and Croatia teams to see who is smiling more [*], but before you do you should know that the links between smiling and success are an example of correlation, not causation. There isn't anything in the study to suggest that smiling causes success, even though you can tell a plausible story about it.
However, you should also know that the correlation between smiling and success isn't limited to football. In another new paper, published in the Journal of Positive Psychology (ungated version here), Lukasz Kaczmarek (Adam Mickiewicz University, Poland) and co-authors looked at the correlation between smiling and success for scientists. Using data for 220 male and 220 female scientists taken from the research social networking site ResearchGate, Kaczmarek et al. first coded whether the researchers were smiling in their profile picture, and then looked at whether that was related to a range of research metrics. They found that:
As expected, smile intensity was significantly related to the number of citations, the number of citations per paper, and the number of followers after controlling for age and sex... Smile intensity was not significantly related to the number of publications produced by the author or the number of publication reads.It is plausible that there is causality working in two directions here. More successful researchers (those whose papers are cited more often) are more likely to be smiling, happy people (explaining the correlation between citations and smiling), while smiling, happy researchers are more likely to entice other people to follow them on a social network (explaining the correlation between followers and smiling). However, more work would need to be done to establish whether those explanations hold for a larger sample.
Either way, both studies suggest a strong correlation between smiling and success. Go Croatia!
[HT: Marginal Revolution, for the Kaczmarek et al. paper]
[*] Please note that I take no responsibility for the outcomes of any bets you make as a result of your new knowledge about successful smiling footballers.