Asmir Gračanin et al. on the function of tears
In the inter-personal domain, tears can be considered as a signal that conveys information about the helplessness of the crying individual resulting in increased motivation of observers to react with pro-social behaviour. However, the inter-personal effects of crying are also not always consistent. Although evidence suggests that the perception of tears generally results in helping behaviours, strengthening of social bonds and a reduction of aggression, there is convincing anecdotal evidence that (particularly acoustical) crying may also sometimes evoke irritation and even aggression and violence. The precise determinants of the reactions of others to crying still wait to be disclosed. Nevertheless, it seems obvious that the personality of the observer, the specific antecedent and the perceived appropriateness of crying, as well as well as the relationship between crier and observer may all play a role.
https://www.tandfonline.com/doi/full/10.1080/02699931.2016.1151402