Negative experiences can damage brain development by slowing synaptogenesis, pruning, and myelination. Experiences such as poor nutrition, exposure to secondhand smoke, family stress, and child abuse or neglect may have profound, long-term effects on the development of a child’s brain.
For example, when a child has a negative experience such as being yelled at and criticized, her body responds by releasing chemicals that control the brain and activate the survival instinct. When in the survival mode, many of the body’s systems slow down. If the body remains in the survival mode for an extended period of time, brain development and physical growth may slow down or even stop.
The damaging effects of negative experiences depend on three factors:
- Amount of Exposure. Brains exposed to a greater amount of a negative experience are more likely to show significant damage.
- Duration. Brains exposed to negative stimulation over a longer period of time are likely to sustain more damage.
- Timing. Negative experiences during key sensitive periods in development are most likely to damage specific parts of the brain.