Scientists who eavesdropped on nearly 1,000 conversations around the world report that people who receive favours rarely say ‘thank you’.
To test that idea, Simeon Floyd at San Francisco University of Quito in Ecuador and his colleagues obtained informed consent to install cameras equipped with microphones in homes and public spaces on five continents, allowing the researchers to record conversations in eight languages.
The team recorded almost 1,000 examples of people asking for a favour — such as a request for a cigarette — and receiving it. In only 5.5% of those cases did the recipient express appreciation with either words or a gesture. Speakers of Cha’palaa, an unwritten language spoken in Ecuador, did not once express thanks in 97 exchanges that included a favour being requested and granted.
The results indicate that explicit gratitude is not a universal social currency. Instead, people help each other on the assumption that others will help them.