This paper deals with the origin and development of the gender resolution rule according to which the predicate adjective agrees with the masculine antecedent when there is agreement with a conjunction of subjects at least one of which denotes a male person. Apart from Croatian, such a rule exists (or existed) in the other Slavic languages, as well as in Baltic languages, so it can safely be posited for Proto-Slavic and Proto-Balto-Slavic. We further show that most contemporary and ancient Indo-European languages had such a gender resolution rule. Where such a rule does not exist (as in Germanic languages), there is a plausible historical explanation. In Hittite, which preserves the most ancient gender system of Indo-European (with only common and neuter genders, and no feminine gender), the default agreement is with the common gender noun. Recent advances in our understanding of the development of gender in Indo-European allow us to show that the rule taking the masculine as the default gender has developed from the rule taking the common gender as default. This is because the morphemes showing gender agreement on adjectives and pronouns of the masculine gender have developed from Early Proto-Indo-European morphemes expressing the common gender.; U ovom se radu raspravlja o podrijetlu i razvitku pravila za razlučivanje roda, po kojemu je predikatni pridjev muškoga roda kad se slaže s više subjekata od kojih barem jedan označava mušku osobu. Osim u hrvatskome, takvo pravilo o zadanoj sročnosti postoji ili je postojalo i u drugim slavenskim jezicima, kao i u baltijskim jezicima, koji su slavenskima genetski najbliži. Nadalje se pokazuje da većina suvremenih i starih indoeuropskih jezika ima isto takvo pravilo o zadanoj sročnosti, a u onima gdje takvo pravilo izostaje (npr. u germanskim jezicima) postoji povijesno objašnjenje za to. U hetitskom jeziku, koji čuva najstarije stanje sustava roda pripisivo ranoindoeuropskome prajeziku (razlikuju se samo opći i srednji rod, a ženskoga roda nema), zadana je sročnost s imenicom općega roda. Na temelju suvremenih spoznaja o razvitku kategorije roda u indoeuropskome pokazuje se da je pravilo o zadanoj sročnosti u muškome rodu nastalo iz pravila o zadanoj sročnosti u općem rodu zbog toga što su nastavci koji pokazuju sročnost na pridjevima i zamjenicama muškoga roda postali od ranoindoeuropskih nastavaka općega roda.