personal history是个什么？

今天看了一个学校的要求，让写personal history，具体的要求如下：Upload or enter your Statement of Personal History, which should not duplicate your Statement of Purpose. In this separate essay you should discuss how your personal background informs your decision to pursue a graduate degree. Please include any educational, familial, cultural, economic, or social experiences. challenges, or opportunities relevant to your academic journey. How can you contribute to social or cultural diversity within your chosen field or serve educationally underrepresented segments of society with your degree. 有没有哪位大神写过？给几个例子呗。。大概要写多少？