We've heard it time and time again – trust and honesty are two of the most important parts of the foundation for any healthy relationship.

But could lying actually help you and your other half to last the distance? According to science, that could indeed be true – as long as you're lying to yourself.

Researchers in Buffalo, New York, monitored around 200 couples over the period of a few years. Each half of the couple was asked individually at various times about how they felt about the quality of their relationship, and also about the traits they felt an "ideal, imaginary partner" would have.

One glaring observation the researchers noticed? Many of the couples felt that their other halves were very similar to the idea of Mr/Ms Right they had in their head – even if their spouse didn't report those traits in themselves.

So while you might say your partner is super-thoughtful for the surprise delivery of roses that arrived at your door on Valentine's, they might not necessarily think of it that way themselves – especially if the "surprise" only came about as a result of a frantic reminder text about Valentine's from their mum/sister/BFF.

According to the researchers in Buffalo, the couples who think better of their spouses – regardless of the reality – did better in the long run, because each half of the couple wanted to work to live up to their partners expectations.

Basically, your positive reaction to those last-minute roses might be the exact thing that spurs your other half on to do something extra special next Valentine's, just to keep you smiling.

Of course, the researchers warn that this advice certainly does not apply to more drastic situations like abuse or downright unhealthy relationships – but they noted that for couples who were already in a good place, a little delusion could go a long way.