Territorial animals are known to be able to differentiate between intruding individuals posing a low or high threat and adjust their aggressive response accordingly. However, plastic territorial aggression based on recognising individuals with different attributes is typically assumed to be relevant only in the context of conspecific interactions. In this study, we investigated territorial aggr...

Social exclusion increases aggressive behaviour, and the possible neuroendocrine underpinnings of the effect are largely unknown. Here, we examined the extent to which testosterone and cortisol responses to social exclusion would predict subsequent reactive aggression. Men were randomly assigned to a social exclusion (SE) or inclusion (SI) condition of 'Cyberball', a computer ball-toss game. Ag...

High levels of aggressive behaviors against intruders in the nest area are displayed by female rats during the first 10 days after delivery, declining thereafter to very low levels, even though lactation continues. Cross-fostering experiments were undertaken to test the hypothesis that pup age may affect aggression in lactating rats. The behavior of females on the 8th day after delivery when ra...

In animals, the progress and outcome of contests can be influenced by an individual's own condition, their opponent's condition or a combination of the two. The use of chemical information to assess the quality of rivals has been underestimated despite its central role in the regulation of social interactions in many taxa. Here, we studied pairwise contests between founding queens of the ant La...

Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus). The a...

Introduction: Aggressive behavior is a major issue in the field of mental health. Pharmacotherapy is often used for the treatment of violent individuals. A neurochemical system most consistently linked with aggression is the GABAergic system. The aim of the present investigation was to examine the effect of muscimol (GABAA agonist) 250 and 500 ng/rat and picrotoxin (GABAA antagonist) 1.5 and...