the impact of documentaries

of the many words that were strung together at lucy walker's presentation tonight on the power of documentaries the set I took away was this:

these forms of virtual reality [documentaries, etc.] can prompt people to take the perspective of people unlike themselves and to expand their circle of sympathy.

she seemed to be precise with words used on her slides. I found it interesting that she chose the expansion of sympathy as an impact of documentaries. I'm curious to explore this more - what value does sympathy have? perhaps the first stage of empathy?