Why does time fly or drag? How emotions warp our temporal perceptions

WHEN WE ARE children, short time periods represent a much larger chunk of our lives so far, compared with when we are older. This may lead a 5-year-old to feel that a year is an intolerable time to wait for Christmas, while for an adult, those 365 days fly by.

But there is more to our puzzling contractions of time than that. Some of it is in the brain. Adrian Bejan at Duke University in North Carolina says the brain’s processing speed slows as we age – caused by the greater complexity of our neural networks that means signals travel greater distances. Our ageing brain captures less information per second, so packs less temporal information into one block of time, or “episode” (see “How do we sense time?”). This can create the illusion that time has sped up. When we are younger, experiencing things for the first time may pack more into each episode. Like a slow-motion camera capturing thousands of images per second, it crams more into each time period and your subjective experience is of time passing more slowly.

Moment to moment, our emotional state can affect how we perceive time passing, too. It seems to fly when you are having fun and drags when you are bored. This may be to do with how our body processes time. The theory of “embodied cognition” says it is the processing of physical sensations that creates our perception of the world around us, including our sense of time. The body has numerous rhythms, after all – from the beating of the heart to the hunger in our stomach – that …