The video below is showing how a toddler reacts to an angry person. It interrupts their focus from fun and learning and puts all of their focus on the angry person. If you watch, you will see the child just stops. The child in the video doesn’t know what to do, except he appears to be bracing himself for what may come.
Think about this child in terms of a nasty, angry co-parenting situation, caught in the middle of two angry parents. While the parents may not be angry all the time, it may be enough to refocus the child’s attention on the battle, and not school or friends or other happy experiences. This is a good reminder to keep those feelings of anger in check during your parenting time with your child, and to do your part to keep the conflict with your co-parent at a minimum. This is not to say that you should blame the other parent for their anger, or try to control their anger, because you cannot. You can only control yourself. However, your decreasing reactions may have a counter effect on the other parent. It is hard to be angry to someone who is not helping to fuel that fire.