“…Similarly, Murube et al (1999) theorized that tears, beyond functioning as a request for help, also serve as a signal for offering help, for example in situations involving expressions of sympathy. Consistent with this, Provine, Krosnowski, and Brocato (2009) argued that emotional tears reliably signal sad feelings of the crier (see Cordaro, Keltner, Tshering, Wangchuk, & Flynn, 2016, for similar findings with regard to the acoustical attributes), and additional studies found that perceptions of sadness foster support behavior in others (Lench, Tibbett, & Bench, 2016). Interestingly, although mammals and certain bird species show distress vocalizations when being separated from a caregiver, humans seem to be unique when it comes to the production of emotional tears, which is maintained throughout the lifespan (Vingerhoets, 2013).…”