The practices of Cambridge Analytica, a data-analytics firm involved in US President Donald Trump’s 2016 election campaign, have made headlines around the world this month. It’s alleged that the firm received data from millions of Facebook users, gathered without their explicit consent. Media reports suggest that this data hoard was later used to target voters with messages personalized to their personality traits — a strategy known as psychographic marketing — although the firm has denied that it used the Facebook data in its work.
But could these tactics actually have swayed voters? In this article, Nature takes a look at the science behind psychographic targeting.