As a twin, and a dad to twins whose other dad is also a twin, I know a thing or three about shopping for two. And these days, twin gift ideas have never been more necessary: the number of twin births has nearly doubled over the past two decades in the U.S., mostly due to the advent of assisted-fertility technologies.

While twins may share birth dates and physical characteristics, that does not necessarily mean they share the same taste in toys and games and goodies. “You need to find gifts that match each twin’s unique personality,” explains Ilene Gayer, owner of Hom-Bom Toys on New York’s Upper East Side. She’s also the mother (and boss) of identical-twin daughters, Alison and Melissa, who can often be found working the counter together. Alternatively, Gayer says, you can go with something that offers “the opportunity to make things together,” like a science project.