Today, more than four billion people spent an average of several hours a day on social media sites such as Instagram, Facebook and Twitter. What drives people to be active – sometimes obsessively so - on social media? Lindström and Amodio, working together with colleagues from Sweden, the Netherlands, the US and Switzerland, tested whether one explanation could lie in the way our brains learn from rewards.
The research team analysed more than a million posts from over 4,000 users on Instagram and three online forums (on men’s fashion, women’s fashion and gardening). ‘We saw that people spread their posts in such a way that the number of likes they receive on average is maximised. They post more frequently after they get a high number of likes and less often when they receive fewer likes,’ says Lindström. The authors used computational models to show that this pattern conforms closely to known mechanisms of reward learning, suggesting that social media engagement is driven by similar principles that lead non-human animals, such as rats, to maximise their food rewards in a Skinner Box. The Skinner Box, named after American academic Burrhus Skinner, is an instrument for changing animal behaviour through reward learning.
The researchers then sought confirmation of their results by conducting an online experiment on an Instagram-like platform. Participants could post funny images with phrases or memes and they received likes as feedback. The experiment also showed that people are more likely to post if they receive on average more likes.
The researchers concluded that social media use thus follows the basic principles of reward learning. ‘Our findings can help lead to a better understanding of why social media dominates so many people's daily lives, and can also provide leads for ways of tackling excessive online behaviour,’ says Lindström.
Björn Lindström, Martin Bellander, David T. Schultner, Allen Chang, Philippe N. Tobler and David M. Amodio: 'A computational reward learning account of social media engagement', in: Nature Communications (26 February 2021) ). DOI: 10.1038/s41467-020-19607-x