Beta romantic relationships tend to start from intense exchanges of emotions, either of a playful, aggressive sort, or of a more "tormented" sort based on personal images of special meaning, "romantic" in a 19th-century sense. The two sorts merge together to make Beta the quadra most inclined towards "romantic courtship" in the everyday sense of the term.
A relationship is felt to be "lacking" if not accompanied by intense demonstrations of emotions. Romantic relationships are also held together by a sense of common goals and purpose, and of the other person as the best partner towards achieving them. Betas are the most intense of all quadras in terms of exchanges of emotional and sensual interplay.