It's the age old dilemma. You're laden with groceries, and you're trying to do trolley maths in your head to figure out which queue will move the quickest. We have three questions that you should ask yourself when picking a queue, which greatly increase your chances of picking the fastest, and it has nothing to do with the ratio of people to items. In his book, Why Does The Other Line Always Move Faster?, author David Andrews explores the psychology of supermarket queues. While he confirms that because of the specific way our brains perceive time, "regardless of time actually spent, the slowest line will always be the one you're standing in", he did include tips to make the most informed choice when picking a line. According to Andrews, you should ask yourself these three questions: Which queue has more men?  This might sound like a strange one, but it's down to the fact that men have less patience and are more likely to give up quicker. Which queue veers left?  Most people are right-handed and instinctively turn right, so the left hand queue is probably shorter. Is there a "cash only" line? Seems like a no-brainer but you may not have really thought about it before. Card users take longer and this has been confirmed by numerous studies. So if there's a cash-only queue, join it. Obviously if one queue clearly has fewer people these questions don't apply - but if it's a toss up, you're probably on to a winner with these.