Cooperating to show that you care: costly helping as an honest signal of fitness interdependence

Barclay, Pat; Bliege Bird, Rebecca; Roberts, Gilbert; Számadó, Szabolcs [Számadó, Szabolcs (Elméleti biológia...), author] Lendulet Research Center for Educational and Ne...; Ecology and Theoretical Biology Research Group ... (ELTE / ELU FoS / Bio_I); Department of Sociology and Communication (BUTE / FESS)