Jealousy is when you react negatively towards the possibility of losing what you have to someone else. Unlike envy, it usually involves three people, rather than just two: you, the person who has what you want and the person who threatens to take it away. It's an unhealthy habit that can make any kind of relationship crumble; if you're a jealous person, you have seen how much damage it can do. But at the core of jealousy are some fears and expectations that are hard to shake, unless you make a conscious effort to cast them away.

Bite your tongue. When you feel jealousy taking over, don't react in a destructive way. Don't accuse, don't give the silent treatment, don't roll your eyes, and don't show any signs of displeasure. Try to do the opposite of what a jealous person would do. If a friend is going to spend time with someone else, for example, recommend a good movie or restaurant. If your partner is talking to someone else, leave them be. Do what a completely trusting person would do in your shoes, even if it makes you feel crazy. Jealous behaviour can bring any kind of relationship to its knees, so nip it in the bud. Make time to discuss, using nonviolent communication, what made you feel jealous later, when the strong feelings of jealousy have passed, and you're not as likely to overreact.

Recognise that jealousy is a self-fulfilling prophecy. When you behave jealously, you don't respond to someone's behaviour—you respond to what you believe someone's behaviour implies. In other words, you're reacting to a scenario in your mind that you fear, but that hasn't happened yet, and might not happen at all. By playing with another adult, for example, your child isn't doing something inherently wrong. Neither is your partner who calls to offer condolences to their ex whose mother just died. But your negative reaction to what you believe their behavior implies (that someone else is somehow better than or more important than you) will make the person feel defensive and paranoid, because they're being accused of doing something bad. The more defensive and paranoid they get, the more suspicious and jealous you get. It's a vicious cycle that's difficult to reverse.

Build self confidence. Jealousy is usually a by-product of insecurity and low self-esteem. Sometimes it's a deep-rooted fear of abandonment that someone will leave you, or withdraw their love or attention from you because you're "not good enough"—if so, you need to learn that other people's behaviour and lives are not a reflection on you. Confident people know that even when they are rejected or ridiculed, it's not always because they failed; sometimes people are just short-sighted. And even if they do fail, it doesn't reduce their worth; it simply means they need to learn something new.

Stop feeling entitled to all of a person's time. If you get jealous when you see someone you care about interacting with or spending time with someone other than you, then you need to consider "How much of this person's time do I really want?" It's understandable if you want to spend a certain amount of quality time with your partner, child, parent, or friend. If they're not spending any time with you, then your concerns are valid. But if they spend a good deal of time with you but you never feel like it's enough, and deep down you'd prefer it if you were together all the time, then it's not healthy. Find other activities, and other people to do them with, to fill your time.

Trust. If you get jealous easily, you've probably had your trust broken. Most of the time, the trust was broken in the past, and you inadvertently project your fear of being hurt again onto someone else. The question you need to ask yourself is whether this person (the person who you worry will hurt you) has ever done anything to break your trust in the past. If the answer is no, then it's important to give them credit for that, and not treat him or her like a criminal. If the person has broken your trust in the past, then it's time to forgive, or else jealousy will ruin the relationship.

Period.