Individual traits that predict behaviour.
One of the important ways in which 21Pictures differs from other dating sites is that you get to suss people out by looking at pictures of their lives, rather than by analysing written self-descriptions or lists of attributes. The aim is to encourage people to make intuitive judgements about who they might want to date, similar to how we do it in the "real" world.
Sometimes, though, intuitive judgements can lead us astray. Everyone sees the world through the lens of their own experiences and beliefs, and it’s easy to think that we've "got" someone based on a few scraps of information, such as how they look. We're great at fitting people into boxes. Often we get it right. But not always.