Anger

Two factors go into the formulation of anger: current vulnerability and magnitude of the perceived threat. Relatively little threat will cause anger when vulnerability is elevated, for example when physical resources are low - you're tired, hungry, sick, injured, depressed, anxious, stressed - or when self-doubt is high, making you more easily insulted.

Problem anger (that which leads you to act against your long-term best interests) is caused by high vulnerability. It is the most self-revealing of emotional states, pointing directly to a powerful cause of vulnerability: a sudden drop in core value.

You experience a state of core value when you think and behave in accordance with the most important things to and about you. It includes a sense of authenticity (you feel genuine) and self-regard, which, together, lower self-doubt and vulnerability to threat.
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For instance, if it is important to you to be fair in your dealings with others, you will regard yourself well as long as you are fair, and feel guilt and shame when you are not. If you use the guilt and shame as amotivation to be true to your core value, i.e., to behave more fairly, your self-regard will instantly improve; you will act with conviction and not need anger for defense.