TL;DR: Talk to your child often about their feelings and give them a rich emotional vocabulary/lexicon.
Four years of age is a good time to start teaching a child to learn to handle their emotions themselves in socially appropriate ways. As you so poignantly pointed out, many people don't do this. In fact, the majority of adults often don't manage their emotions properly because they are unaware of primary and secondary emotions, and quickly devolve to easily handled emotions (like anger) or making others responsible for making them feel better. That's why anger management courses are ordered so often by judges for relatively minor infractions. The primary focus of anger management courses is to recognize one's feelings, then deal with them appropriately. They give the (adult) students an emotional vocabulary.
The first step to learning how to handle an emotion is to name it.
In order to correctly perceive feelings in yourself and others, you first have to have words for those feelings, a feeling lexicon. Many children are either “happy” or “mad” and miss all the subtle gradations of feelings in-between because they do not have labels and definitions for those emotions. A large and more complex feeling vocabulary allows children to make finer discriminations between feelings; to better communicate with others about their internal affective states; and to engage in discussions about their personal experiences with the world.
To obtain a list of emotions to discuss, google emotional vocabulary; use one aiming higher than you think your child can handle.
Next, identify your own feelings and have a conversation about them with your child. They will pick it up rapidly if you do this regularly.
Some examples of expressing your feelings in front of your child:
-That noise is so loud. I feel irritated.
-Look at all these bubbles! It's exciting! It makes me feel joyful!
-I'm a little bit afraid of the monster in that book. Are you? You're not? You're brave!
-I tripped in front of everyone. I'm so embarrassed.
-Look at that butterfly. I so glad to see it. I feel grateful.
-Is no one paying attention to you? I feel lonely when that happens to me. How do you feel?
-I feel uncomfortable when I see someone yelling like that. I think I feel a little bit scared, too.
If, for example, a child starts expressing themselves with anger, if they have no emotional vocabulary, you can't explore why they use that behavior in a situation. With a feeling lexicon, you can explore it with them.
I don't think you should tell them what emotion you think they were feeling until you've explored several of their own offerings; a child's offerings will initially be generic (mad, sad, happy). You can offer possibilities deeper than these.
Before, when you got angry with (playmate), what were you feeling? (e.g. answer: "mad") But what made you mad? Were you feeling jealous? (yes/no) Were you feeling ignored? (yes/no) (unloved/unimportant/frustrated/etc.?) if you get all "no", you might take an educated guess ("I think that maybe you felt unimportant, because (friend) wasn't playing with you. Is that right?") Then discuss how to handle feeling unimportant.* Talking about it in a place of safety and acceptance, you can help the child work out different strategies to deal with feelings.
This is already a long answer, but the other important strategy in helping your child emotionally is to teach them resilience. It comes naturally to some people, but it is a teachable skill.
Resilient people have
- close relationships with family and friends
- a positive view of themselves and [reason-based] confidence in their strengths and abilities
- the ability to manage strong feelings and impulses
- good problem-solving and communication skills
- feelings of being in control
- know how to seek help and resources
- see themselves as resilient rather than as a victim
- cope with stress in healthy ways and avoid harmful coping strategies, such as substance abuse
- help others
- find positive meaning in their lives despite difficult or traumatic events
Isn't this what we all want for our children?
* Easier said than done. First, validate the feeling ("It's OK and normal to feel [x]; everyone feels [x] sometimes; I know I do.") Then, depending on the circumstances, suggest possible actions ("Ask [playmate] if they're still interested in playing [y], or does [playmate] want to play something else?" That's one solution.)
My recently turned 3 yr old grandchild was looking at fireflies, and when I asked them how they were feeling, they answered, simply, "I feel serene." I did, too.
A prime scenario used in anger management courses is road rage. Why do we get angry when someone cuts us off in traffic? It can be that we were afraid of being in an accident, or that we felt disrespected, or unimportant, etc. Then how to handle it? Think of the other driver. Maybe they were unaware of your vehicle. Maybe they were distracted. Maybe there is some emergency they need to attend to. Maybe they're just inconsiderate jerks. In all those scenarios, it's not about you, it's about them. When you really incorporate that, the anger is reduced or eliminated.
Enhancing Emotional Vocabulary in Young Children
The Road to Resilience