Lovers' hearts beat in sync, study says

(Medical Xpress)—When modern-day crooner Trey Songz sings, "Cause girl, my heart beats for you," in his romantic ballad, "Flatline," his lyrics could be telling a tale that's as much physiological as it is emotional, according to a University of California, Davis, study that found lovers' hearts indeed beat for each other, or at least at the same rate.