As described in Section 3.2, these descriptions involve social interactions, typically actions (e.g., 'kiss') performed by one or both of the people concerned (e.g., 'Jacob kissed Rachel and began to weep').
to determine whether the two people are involved in a social interaction, we first check whether the two named entities were marked in the dependency tree either as a subject-object pair of a verb, or as a pair connected by a coordinating conjunction (e.g., 'and'), serving as a subject or object.