Not wanting to interrupt people
Self filtering increases as potential risks of saying things increases - also latency of filter
Potential benefits of saying things also increases - I am too risk averse
Usually risks are pretty low (though feel worse than they actually are), high upside
Conversation topic is often something I'm not that interested in
Sometimes I'll talk more in a group if it's something that I have a lot to say about or I'm with people I feel comfortable around