White people don't like being left out. No one likes being excluded but white people especially don't like it because they are not used to it. White people have always been included in everything (except slavery) and it disturbs them when they feel like they are missing out on something.
In order to preempt any feelings of exclusion, white people go to great lengths to be a part of everything they can find: neighborhood associations, political groups, animal rights organizations, booster clubs, parent-teacher groups, book clubs, country clubs etc. White people are game for anything that entitles them to a card certifying their membership and requires them to pay dues.
In addition to pointless memberships, white people are also known to employ a less difficult, but just as effective, tactic for avoiding exclusion: gossipping about the people around them. Never underestimate the power that this behavior can provide. It serves two functions: one, it includes them in "the loop" of people who know the information and two, it provides them with firepower if they ever need to launch a quick counter-offensive against someone who is attempting to exclude them.
"Sorry Sharon, I wish you could go to lunch with us but its just the people from acccounting that are going."
"Oh ok John. Hey, I just heard you have a nasty case of IBS. I'll ask around the building while you're gone to see if anyone knows a good doctor."
"You know what Sharon, just come with us".