Choose one of these five pens to discover what your selection says about your class. All of the pens write in black ink. Go ahead, pick one...

If you identify as working class, then there is a 72% chance that you picked the green (majority) pen, and 28% chance you picked the orange. If you identify as middle class, then your pen choice is much harder to predict, but it’s slightly more likely that you picked the orange pen (58%) than the green (42%). These were the findings when this study was run under test conditions at Stanford University. Why? Well there’s nothing special about orange versus green. There is the same pattern of majority versus minority even if the colours are reversed.

Instead, the authors suggest that their finding is due to the fact that middle-class values emphasise choice, individuality, and going against the grain, even in matters as trivial as picking the minority pen. In contrast, working-class values (which the authors characterise as “it’s not just about you”) emphasise fitting in. Of course, as is always the case with these types of studies, the finding that working-class people are more likely to choose the majority pen is merely a statistical generalisation – the study was only 50 people. And, of course, all this is totally trivial when it comes to choosing a pen.

This article was amended on 4 December 2016 to clarify that all of the pens write in black ink.

A fully referenced version of this article is available at benambridge.com. Order Psy-Q by Ben Ambridge (Profile Books, £8.99) for £6.99 at bookshop.theguardian.com