<p>WestCoastKid101 ~ </p>
<p>This is too late to help you, but maybe it will help someone else reading this thread in the future. You ask what kind of “summer activities you participated in during high school”; my best advice, as the mother of a Caltech student, class of 2014, and a Stanford student, class of 2017, is that you need to do what interests YOU. Develop your passions, follow them as far as your current environment will allow - and let the chips fall where they may. </p>
<p>BTW neither of my children had a “hook”. They got in because they were A) lucky (I make no claims that they were superior to the rejected applicants, only that they were qualified.) and B) able to express their individual passions in their admission essays. Not fakey-fakey “make a good impression in the essay” stuff, but real passion. With regard to Caltech specifically, if you are not passionate about doing science and research, you won’t like it there; ignore the weather and go to Harvard instead. It is much less demanding for undergraduates. Only a person who actually likes to study and do homework - actually likes it - will be happy at Caltech.
Good luck!
P.S. Parents: I did not “help” either of my children with the admission process. If your child is able to thrive in a high quality institution, then they are able to apply on their own and write their own essays. That’s my opinion anyway. (I didn’t help them with their homework, either!) </p>