Consider this:
  • Louis Vuitton bags are correlated with being rich.
  • Therefore, to become rich, purchase Louis Vuitton bags.
Does this seem silly?

Yet, people propose that we should aim to be monogamous, and stick with one partner; not because we want to be monogamous, and have found someone we want to commit to; but because monogamy is correlated with happiness.

Imagine three couples:
  • Couple A are both mentally healthy, and are a good match. Because they are a good match, they do not seek other partners. They live together happily, and for a long time.
  • Couple B are both mentally healthy, but are not a good match. Because they are not a good match, they divorce. They each find new partners, and become happy.
  • In couple C, one is mentally healthy, the other isn't. Because of this, the relationship suffers. Eventually, they divorce. The mentally healthy partner finds a good match, and becomes happy. The other goes through several relationships before getting help, and then finds happiness.
Consider the statistics this creates. Simply because of couple C, happiness is correlated with monogamy. But this does not mean couples B and C would be better off not divorcing.

In order to find happiness as part of a couple, you must first be a person who can have a relationship. Then, you have to find a partner who is a good match.

Once you have become this person, and found a right partner – it doesn't matter if you're monogamous. You probably will be monogamous, because neither of you will need other people. But if you want to explore non-monogamy with this partner, that is also just as fine.