These relationships are the most favourable and comfortable of all intertype relationships providing complete psychological supplements. Dual partners are like two halves of a whole unit. They usually understand each others intentions without any need to say a word. Dual will naturally protect your weak points and appreciate the strong ones without asking for anything in return. Interaction with your Dual allows you to be yourself without the need to adjust to your partner like in other relationships. This often saves both partners a lot of energy which they can use for their own interesting activities. Conflicts between Duals are very rare and if there are any, they are normally short lived and solved without pain. Your Dual partner will love you just for what you are and if there is such a thing as true love then it could probably only occur in relationships of Duality.
However, let's not idealise these relationships too much. Although theoretically relationships of Duality are the best of the best, practically not everybody who is your Dual will make your dreams come true. The reason for this is that we are usually so twisted up during the course of our lives that our already formed and stable views and attitudes can affect our relationships quite heavily. In fact, younger people have more chance to succeed in the quest for their perfect partner than older people. But the chances are always there.
There are at least two conditions to be completed for a successful relationship between Duals. Firstly between the partners there has to be at least a minimal mutual attraction. Secondly and most importantly is that the partners are truly striving for the same or similar things. This may include common interests and/or life goals. Partners that are both seriously thinking about building a family are a good example. Logically saying: two halves of the same whole must not repel or move in the different directions, otherwise the whole will break into pieces. Relationships of Duality also go through several stages. The first stage sometimes can be really tense. It is like a new engine that requires a "run in" first. If relationships crumble it normally happens in the first stage. The more stages completed by Duals the more unbreakable their relationship.
However, nature has played a little trick on us. It is difficult to notice your Dual partner among all the other types and even easier to pass them by. Usually during first contact extroverts think about their introvert Dual as ordinary and simple, therefore not deserving their personal attention. In return introverts consider their extrovert Dual to be too good for them and therefore unattainable. Both positions usually belong to people who had a lack of Duality interaction during childhood. The magnetic effect of Duality becomes obvious when partners do not see each other for a while. Only after being together for a fair amount of time do the partners start realising how much they need each other. Finally, these relationships are most suitable for friendship, marriage and family life. To have a Dual partner is irreplaceable if you have to compete or survive in a socially dangerous environment.