Communication and cognition.- Visual communication: evolution, ecology, and functional mechanisms.- Vocal communication in social groups.- Kin recognition: an overview of conceptual issues, mechanisms and evolutionary theory.- Honeybee cognition.- Individual performance in complex social systems: the greylag goose example.- Conflict and cooperation.- Conflict and conflict resolution in social insects.- Social insects, major evolutionary transitions and multilevel selection.- Cooperation between unrelated individuals - a game theoretic approach.- Group decision-making in animal societies.- Parental care: adjustments to conflict and cooperation.- Sex and reproduction.- The quantitative study of sexual and natural selection in the wild and in the laboratory.- Mate choice and reproductive conflict in simultaneous hermaphrodites.- Extra-pair behaviour.- Extreme polyandry in social Hymenoptera: evolutionary causes and consequences for colony organisation.- Monogynous mating strategies in spiders.- Mating systems, social behaviour and hormones.- Behavioural variation.- The social modulation of behavioural development.- Alternative reproductive tactics and life history phenotypes.- Animal personality and behavioural syndromes.- Social learning and culture in animals.- Levels and mechanisms of behavioural variability.