Does a rat free a trapped rat due to empathy or for sociality?

Abstract

This report evaluates whether a rat releasing a trapped rat from a restraint tube is better explained as due to its empathic motivation or to the pursuit of social contact. In the first condition, each of six rats chose in an E maze between entering an empty goal box versus entering a goal box where its entrance caused a rat trapped in a restraint tube to be released. Rats preferred the goal box with the trapped rat over the empty goal box. In the second condition, these rats chose between releasing a restraint-tube-trapped rat in one goal box and another rat in the second goal box that was not locked into its restraint tube. Rats showed no preference between alternatives. In the third condition, rats chose between a goal box containing a rat with an open restraint tube and an empty goal box. Rats preferred the rat with the open restraint tube over the empty goal box. These results support attributing the response of releasing a rat from a restraint tube to the reinforcing power of social contact rather than interpreting this response as empathically motivated.

Rats (Rattus norvegicus) find occupancy of a restraint tube rewarding

“…It predicts free rats will prefer the goal box with the rat and the open restraint tubethe very result obtained. Hachiga et al (2018) interpreted these results as consistent with Silberberg et al's (2014) sociality premise. Hiura et al (2018) expanded on the results shown by Silberberg et al (2014) by arranging multiple trials in a session, presenting phases of acquisition and extinction, and varying postsession social restriction.…”

“…There are two reasons for this perspective. First, for Silberberg et al (2014) and Hachiga et al (2018), a sociality account consistently succeeds in accommodating outcomes whereas an empathy account does not. Thus, in terms of parsimony, a sociality account seems favored.…”

“…What is needed is a new design different from those used earlier to corroborate either the empathy or socialcontact hypothesis. Toward that end, Hachiga et al (2018) used an E maze to evaluate the conflicting interpretations of these prior studies. In their first condition, the free rat could choose to go to one goal box that contained a rat trapped in a restraint tube where entrance to the goal box caused the experimenter to remove immediately the door blocking the trapped rat's egress from the tube.…”

Social modulation of drug use and drug addiction

“…Recent studies of pro-social behavior in rats have also demonstrated that rats are able to release a trapped rat from a restraint tube (Ben-Ami Bartal et al, 2011;Hachiga et al, 2018). Similarly, mothers develop a preference for a compartment previously associated with pups (Fleming et al, 1994;Panksepp and Lahvis, 2007) and lever press to gain access to pups (Hauser and Gandelman, 1985) (Lee et al, 2000).…”

Conformity-like behaviour in mice observing the freezing of other mice: a model of empathy

“…However, in these observation systems, it remains unclear whether the observer mouse truly recognises the movements of and empathises with the demonstrator mouse. Given that even humans cannot know exactly what others feel and think, it is necessary to exercise caution when discussing whether mice and rats have an ability to empathise [34][35][36].…”