A team led by Charlotte Debras and Adrian Jaeggi at the University of Zurich's Institute of Evolutionary Medicine organised soccer tournaments with the Indigenous Tsimane in the Bolivian Amazon. The researchers chose the Tsimane because lifestyle can affect hormone levels and social bonds are especially important in interdependent societies. To measure oxytocin they collected urine samples from players before and after matches.
Results showed oxytocin increased most strongly after matches against familiar rivals and less so when teams came from different communities. When the Tsimane played non-Tsimane opponents, oxytocin rose again. The pattern suggests oxytocin responds to the salience of the opposition, with stronger reactions to both familiar competitors and a clearly defined out-group.
There was a clear sex difference: men showed changes in oxytocin around games, while women did not. The researchers noted reasons such as higher baseline levels in some breastfeeding women, less frequent play by women, different meaning of soccer for women, and the "male warrior hypothesis". They also cautioned that the study cannot tell whether oxytocin mainly promotes team cohesion or drives competition with opponents.
Difficult words
- indigenous — People originally from a specific region.
- lifestyle — The way a person or group lives.
- hormone — A chemical in the body that controls functions.
- oxytocin — A hormone linked to bonding and social behavior.
- rival — A person or team competing against another.rivals
- opponent — A person or team on the other side.opponents
- interdependent — Needing each other; connected in important ways.
- cohesion — The action of staying united as a group.
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Have you ever felt different playing against familiar rivals compared with strangers? Why or why not?
- How could team sports help social bonds in your community or school? Give one or two examples.
- Why might men and women react differently to competitive games? Suggest one or two simple reasons based on the article.
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