Neural connections carrying signals from the cortex (the brain region responsible for thought) down to the amygdala (a brain region crucial for emotions) are less well developed than connections carrying signals from the amygdala up to the cortex
Thus, the amygdala exerts a greater influence on the cortex than vice versa
The influence that the amygdala exerts on the rest of the brain is dependent on the influence that the cortex exerts on the rest of the brain.