50.1 – Describe how early experiences can modify the brain. Lab rates raised in an enriched environment developed a heavier and thicker brain cortex and had 20% more synapses. In childhood unused neural pathways weaken and gradually disappear.

50.2 – Describe the ways in which parents and peers shape children’s development.  The power of parenting is clearest at the extremes: abused and neglected children, for example. Two children fro the same family are as different from one another as one pairs of children selected randomly form the population. Children and adolescents are especially influenced by peers (desire to fit it).