<p>Having a sibling at Yale may help you with admissions to Yale, but will have no bearing on your applications to Caltech. Caltech will evaluate you on your OWN merit, and on your OWN demonstratived drive and passions for science. Caltech is less influenced by any outside factors (race, legacy, athletics, etc) than most ANY other college, and looks at the students commitment to driving scientific exploration further and further.</p>