I got this from the internet.
1. Ages 0-6. That is to say, during the time when the child lives at home and the main influences are parents and siblings, up to the child's entry into first grade. (You can take it back a year to Kindergarten, if you want.) This is the child's leaving of the original human community (family) and entrance into the wider human community, represented by school.
2. Ages 6-12, or elementary school to the end of 6th grade. This tends to be somewhat arbitrary, in part because puberty interferes with childhood at various ages. Anyway, the grade school years are the time when what was learned in the family is practiced in the wider world. Thus the child learns to deal with adults other than their parents (their teachers). And they learn to deal with peers (classmates) based on how they dealt with siblings and playmates.
3. Ages 12-18 or the "teen years" are a third stage in learning how to be a person. In a sense, these years repeat the first six years of life. What was learned as a child gets practiced as an emerging adult. This is the last time for the individual to make changes in what will become the "basic" personality at, say, high school graduation.
As life goes on, we change a few things (we can't change much without becoming a completely dfifferent person, and basic personality resists being someone else!!!). Maybe you talked a lot as a toddler, but are now more reflective, or are now more aware of other people, or something else. It's not "conditioning," it's choices you are making as you grow older and mature as a human being. -- Dr. Bob