We study a tug-of-war game between two players using the lottery contest success function (CSF) and quadratic cost (of effort) function. construct pure strategy symmetric Markov perfect equilibrium of this game, show that it is unique, provide closed-form solutions for strategies values. In stark contrast to model with an all-pay auction CSF, exert positive efforts until very last battle in equ...

Perseverance toward goals that carry short-term costs is an important component of adaptive functioning. The present experiments examine the role that the emotion pride may play in mediating such perseverance. Across 2 studies, pride led to greater perseverance on an effortful and hedonically negative task believed to be related to the initial source of pride. In addition, the causal efficacy o...

Both wild and captive chimpanzees (Pan troglodytes) share food with non-relatives. Researchers have proposed several hypotheses to explain this behavior, including ‘food for sex’, ‘food for grooming or agonistic support’, and ‘sharing under pressure’. We examined food sharing in two captive groups of socially-housed chimpanzees. In contrast to previous captive studies, which only examined trans...

Cognitive flexibility can be assessed in reversal learning tests, which are sensitive to modulation of 5-HT2C receptor (5-HT2CR) function. Successful performance in these tests depends on at least two dissociable cognitive mechanisms which may separately dissipate associations of previous positive and negative valence. The first is opposed by perseverance and the second by learned non-reward. T...