In Western cultures, we mark the beginning of romantic entanglement by touching lips. Few actions are as fraught with anxiety and symbolism as that first kiss—and it’s no exaggeration to say that some ...

Why do we kiss our lovers on the lips? We could show romantic passion by rubbing foreheads, locking elbows, or by turning back-to-back and bumping butts. We could even mash our ears together. Legend ...