In those whom I like, I can find no common denominator; in those whom I love I can: they all make me laugh.

Auden distinguishes between the mild, selective pleasure of “liking” and the deeper, more revealing attachment of “loving.” People we merely like may share no single trait; our preferences can be scattered and contingent. Love, however, discloses a unifying thread—not in social category or virtue, but in the capacity to make us laugh. The “common denominator” suggests an almost mathematical reduction: love simplifies complexity into an intimate recognition. Laughter here signals ease, trust, and shared perception; it is a test of emotional compatibility and a marker of intimacy. Auden implies that love is less about admirable qualities than about the spontaneous joy and freedom another person evokes.