How does one write a personal history statement?

[gblob331]

I'm currently writing the personal history statement for the UC applications. The prompt reads as:

Please describe how your personal background and experiences inform your decision to pursue a graduate degree. In this section, you may also include any relevant information on how you have overcome barriers to access higher education, evidence of how you have come to understand the barriers faced by others, evidence of your academic service to advance equitable access to higher education for women, racial minorities, and individuals from other groups that have been historically underrepresented in higher education, evidence of your research focusing on underserved populations or related issues of inequality, or evidence of your leadership among such groups.

My ethnicity is over-represented in the area I'm studying in (theoretical physics) and I grew up in fairly comfortably in a middle class household. I never really volunteered and even when I did it was for tutoring top elementary/middle school kids. Though I do have relatives that are really poor, I've never really met them so I can't really talk about them. So how does one approach this question?

[mandarin.orange]

In a prior incarnation of this same question, I compiled a few links and resources that address it