Perception of risk

Odd thing risk. I was talking to a group of friends yesterday about business. One of the group, a teacher was very quiet for a while as the conversation continued about the various businesses a number of the group are running, what their current challenges are and how they are building new business. The teacher eventually broke her silence and said "I just don't know how you do it. You are all risking so much. I couldn't take that kind of risk. What if your ideas don't work?"
The rest of the group just looked at her for a few seconds blinking. The first person to break the stunned silence said "Actually I see what I do as far less risk than you run being employed. I am my own boss and what happens is in my own hands. If you get a new boss or a new minister or a new government policy you have to go with whatever someone else decides. You have no real say in what happens. If you get good bosses then great if you don't then you have no power. No that for me is a real risk. I can't imagine why I would want to risk my future on someone else making the right decisions."
Today I was party to a different discussion about risk at an investment bank I work with. There was a stock that had been doing well during the morning. One investor was making money on the stock whilst another had decided not to invest because he didn't know enough about the company to make a good judgment. I asked the first investor what he knew about the company involved and he admitted that he knew very little but the opportunity existed in the movement and not the company. The second just shock his head and wandered off. When I caught up with him he laughed and said he needed to know he was going to win as the thought of the potential losses of getting it wrong was just to much. He dubbed it professional suicide.
This began a train of thought. If risk is perceptual are the perceptions catching? Is risk aversion or risk taking purely a personal issue or can it be 'transmitted'?
In organisations where risk aversion is a theme is it because they recruit and foster risk averse people or do people mediate their behaviour and thinking based on the prevalent atmosphere? In effect how much of risk aversion / risk taking is individual and how much is cultural?
Stay tuned as I will report what I find.