Spontaneous mimicry appears fundamental to emotional perception and contagion,
especially when it involves facial emotional expressions. Here we cover recent evidence on …

Rough‐and‐tumble play (RT) is a widespread phenomenon in mammals. Since it involves
competition, whereby one animal attempts to gain advantage over another, RT runs the risk …

Brain sex differences are established developmentally and generate enduring changes in
circuitry and behavior. Steroid-mediated masculinization of the rat amygdala during …

Play is one of the most difficult behaviors to quantify and for this reason, its study has had a
very rocky history. Social play is ephemeral, difficult to distinguish from the other so-called …

This paper aimed to explore and clarify the concept of behavioral flexibility. A selective
literature review explored how the concept of behavioral flexibility has been used in ways …

Gestures and facial displays are involved in regulating many aspects of mammal social life
such as aggression, dominance–subordinate relationships, appeasement and play. Playful …

The commonality of facial expressions of emotion has been studied in different species
since Darwin, with most of the research focusing on closely related primate species …

Differences in play behaviour often illuminate complex ecological parameters and social
differences. In primate societies, including humans, individuals acquire information through …

It is widely believed that juvenile male mammals typically engage in higher rates of rough
and tumble play (RTP) than do females, in preparation for adult roles involving intense …

Many studies highlight the correlation between social ties and fitness, yet often cannot
reveal how ties influence fitness. This review is aimed to facilitate the formulation and testing …