We all take risks when it comes to money—a volatile stock purchase, a high-stakes bet, a $900 pair of Louboutins bought impulsively on final sale. As we get older, however, our ability to take risks changes due to the socioemotional and cognitive-control networks in our brains. In adolescence, the socioemotional network shines (the area that loves social and emotional stimuli), but in older age the cognitive-control network gains strength (cue the planning and self-regulating). It’s the same reason teenagers would gladly drain their savings on a trip to Cancun, whereas adults will tuck it away safely in a 401K. Who has more fun? Jury’s still out on that one.

MORE: At Which Age Are We Happiest?