Something's happened to US campaign slogans. Something affirmative. Inspiring. Motivational. Yes! They've become self-help mantras.

Romney has his rather hectoring “Believe in America” and Obama the grammatically pointed “Forward.” – the much discussed full stop signifying, apparently, a mind set on its course. Last election, of course, we had the rabble-rousing chant “Yes, we can”. The tone now borrows from life coaches where it once borrowed from the advertising industry (“I like Ike”, “Keep cool and keep Coolidge”), and this time it’s much harder to oppose. Agreeing is not only right – it’s healthy!

This would be all very clever, but the trouble with life coaching is that it’s already been through several waves of cultural backlash. If a film features fairground music we know a grisly murder is not far off, and if a character recites motivational mantras, that is a character primed for gentle tragedy. In fact, I’m so damaged by the likes of Little Miss Sunshine and The Office that I can’t hear Romney’s slogan without picturing him saying it in front of a mirror (“I believe in America. I believe in myself. I am a strong, independent individual moving towards a better future”) before bursting into tears and eating Ben & Jerry’s straight from the tub.

But there is also something inherent about the tragi-comedy of motivational quotes. Who really springs into action after reciting a wholesale phrase about how great they are? The slogans seem oddly to derogate you, denying a gap between where you are and where you want to be (“I am the best presidential candidate in the world, ever”) and making the gap all the more apparent. It could only be a matter of time before science found they didn’t work.

A paper published in 2010 in Psychological Science looked at the differences between “declarative” talk (yes, we can) and interrogative talk (can we, though?). The scientists Ibrahim Senay and Dolores Albarracín took 53 undergraduates and gave them anagrams to solve – (for instance, rearranging the letters in “cause” to spell “sauce”). But before they were allowed to start the task they had to spend a minute talking to themselves. One half were in the “Will I?” group – they had to ask themselves whether they could complete the task. The other was the “I Will” group – members had to tell themselves they would. The groups were then given ten minutes to solve as many anagrams as possible.

Any questions?

Raised on Nike adverts and positive thinking, we might expect the assertive group to do better. They were pumped on self-belief, after all, whereas the other group was armed only with mild self-doubt. But no, the “Will I?” group solved 25 per cent more anagrams. Motivation seemed to come from the question, rather than the pre-emptive answer. The researchers thought that the question helped people to tap into intrinsic motivation – whether they actually wanted to do the activity for themselves. They found they did. The extrinsic hectoring in fact blocked their internal motivation. So there we are, Obama, just a small change in punctuation is needed. “Forward?” Yeah, go on then.