For example fear is often a good indicator that you've invested too much or your investment is perhaps not fully researched.
Investing more than you can afford is definitely a contributing factor to fear, but it only adds fuel to the fire. People in general are bad losers, especially if the price does the opposite of what they assumed it would do.
Fear kicks in whenever people lose confidence, which is when they are on the losing side of a trade, regardless of it being your family savings or some pocket money. People at all cost want to try avoid losing.
Don't forget that the smaller the amounts are that people trade or invest with, the higher the risks are they expose themselves to, all because of how people aim to profit big, which is why leverage platforms have gained so much popularity.
Naturally we are. However, and I can only speak for myself in this regard. I get a level of sadness and disappointment if an investment goes the opposite direction to that which I expected but I have never experienced fear when investing a sensible amount, because I know whatever happens I'll still have what I need to survive and be happy.
The point about smaller amounts being higher risk is a very good one, mostly people don't have the patience required to start small and steadily work their way up.