Falling in love can be exhilarating, but it isn’t the secret to marital happiness. “Passionate love”—the period of falling in love—often hijacks our brains in a way that can cause elation or the depths of despair. But, according to researcher Arthur Brooks (writing in The Atlantic), the secret to happiness isn’t falling in love; it’s staying in love. Brooks writes:

This does not mean just sticking together legally: Research shows that being married only accounts for 2 percent of subjective well-being later in life. The important thing for well-being is relationship satisfaction, and that depends on what psychologists call “companionate love”—love based less on passionate highs and lows and more on [friendship], stable affection, mutual understanding, and commitment.

Passionate love, which relies on attraction, does not typically last beyond the novelty of the relationship … As one researcher bluntly summarizes the evidence in the Journal of Happiness Studies, “The well-being benefits of marriage are much greater for those who also regard their spouse as their best friend.”