title: [Cramped like in a sardine box].
authors.forename: Angelika
authors.initials: A
authors.lastname: Staub
mesh_terms: D000533:Altruism; D002648:Child; D002652:Child Behavior; D004493:Education / Q000379:methods*; D005858:Germany; D006379:Helping Behavior; D006801:Humans; D012574:Schools / Q000639:trends*; D012919:Social Behavior