Most of our core beliefs good or bad originate in childhood.
In the first 6-7 years of life, children has 'absorbent mind' which means their brain soaking up everything from their environment (what is 'good', what is 'bad', what is 'safe', what is 'dangerous'...ect). The resoning of a human being developing after that age so until then they have no filters, they are not questioning anything, they absorb everything as it comes.
So when you keep criticizing your kids, they create negative beliefs about themselves (they are not good enough, they are unloveable, they are not important, they are a failure... ect) so they will stop loving and believing in themselfs, they will develop low self-esteem and self-confidence, which then will follow them through their lives.
Generational patterns / Family stories:
Beliefs which have been passed on through generations.
If we don't aknowledge and change the beliefs we gain, they will effect our lives and we will raise our kids by them so we pass these on to our children and they will to theirs.
For example : Negative beliefs around money - Money blocks are mostly generational patterns.
Belief systems are the stories we tell ourselves to define our personal sense of reality, how we individually 'make sense' of the world around us. Its the invisible force behind our behavior and decision making. The ways in which we react in certain situations.
The main purpose of the belief system is 'survival'. It is your subconscius mind's way to protect you from harm (phisycal, mental or emotional harm).
We gain our beliefs through influence of other people, our surroundings and personal experiences.