Mason Lab
UChicago Logo

Our Mission

At the Mason Lab we are currently interested in the presence of empathy and helping behaviour in rats.

Empathy Phonetics



: the feeling that you understand and share another person's experiences and emotions : the ability to share someone else's feelings

Rats will deliberately, intentionally, and rapidly free a trapped cage-mate.


In collaboration with Professor Jean Decety and graduate student Inbal Ben-Ami Bartal, we developed a paradigm in which rats show pro-social behavior (Ben-Ami Bartal, Decety, and Mason 2011). For 12 daily sessions of an hour each, a rat is placed in a restrainer while his cage-mate is free to roam in the arena. The restrainer has a door that can be opened only from the outside by the free rat. For a rat, the door is moderately difficult to open and the they cannot use vision alone to deduce how to open it. Instead, the free rat must discover how to open the door by trial and error.

Rats have to figure out their own way to open a restrainer. Here's a video showing the three most common tactics used by rats.




Paradigm Phonetics



: a model or pattern for something that may be copied : a theory or a group of ideas about how something should be done, made, or thought about

Chocolate loving rats will free a trapped rat and share its chocolate.


We placed rats in an arena with two restrainers, one with a trapped rat and one with 5 pieces of chocolate. The free rat would open both restrainers, and even though the free rats will eat 7 pieces of chocolate outside of an experiment, during the experiment, they only ate 3.5 pieces, saving 1.5 pieces for the trapped rat.





Empathy facilitates social cohesion. Empathy increases the inclusive fitness of organisms by enhancing survival in a variety of ways (e.g., providing increased defence against predators) and serves to bond individuals to one another, especially mothers to offspring. The most basic expression of empathy is emotional contagion, the transfer of an emotional state from one individual to another. This capability has been shown to exist in both humans and non-human animals.