what causes cupcakes to shrink?

Shrink in what way? Can you describe what results you got, what recipe, how you mixed it. Is this your first time making them? What oven temp.

There are so many reasons why. It helps to have more information in order to make a more intelligent answer.

WOW, I was just about the same question.
My vanilla cupcakes always shrink like mega small I fill with a ice cream scooper, the oven is set @ 350. I use box cake but also add ingredients. Mine shrink, look like i didn't have enough batter to fill it, but i do. They come out so small.

I hope I answered all the questions. Please cause I need help

Thanks in advance

In my experience, shrinking can be caused by overbaking, or not taking them out of the pan quick enough (therefore they continue to bake in the pan). Just my 2c. But Linda is definitely a baking science whizz so I would love to hear what she says too.

I also have this same problem, but only when I make vanilla or vanilla w/chocolate chip cupcakes! I use the exact same qty of batter that I use for all other flavors!