Pessimistic means being negative.
1 Now faith is being sure of what we hope for and certain of what we do not see.
2 This is what the ancients were commended for.
3 By faith we understand that the universe was formed at God's command, so that what is seen was not made out of what was visible.
But the man who has doubts is condemned if he eats, because his eating is not from faith; and everything that does not come from faith is sin.
Faith is defined here as something we are sure but we do not see. Being pessimistic (negative mind and thinking) means not having faith and not seeing things with faith. What we see today is not made out of visible but invisible.
Many times as parents especially the so called educated parents think ourselves as very intelligent and analyse every aspect of visible thing in and around children's life. Where there is negativism there is no faith. Where there is no faith, there is no pleasing God. Where there is no pleasing God, there is only sin.
So anything that we think, say or do that does not come from faith is sin. Many times in the name of being realistic, we operate in negativism without faith. Children become exasperated when thy repeatedly hear from their parents that the glass is half empty. The same reality could be perceived as that the glass is half full.
This kind of parents usually justify their negative approach as being realistic and through. They do not want their kids to be disappointed in life by being unrealistic.
They think they are preparing the kids for the worst and to face the horrible world. This has so much to do with their childhood of growing up in a negative family environment in which they are afraid of making mistakes. They find it easier not to be hopeful at all than get disappointed, hence get negative. Children will experience exasperation because of such negative interactions from their parents.
Say to each child 10 positive statements about their life / world.