Using Maximum Likelihood and Bayesian phylogenetic comparative methods, this study aims to answer how cultural meanings and linguistic forms develop in kinship terminology focusing on sibling terminology. It tests sequential models of change of sibling terminologies among the Austronesian language family to reconstruct: the historical state and evolutionary change of relative age and relative sex; whether these distinctions have independent or dependent evolutionary trajectories; and whether opposite-sex distinctions might have developed when no such distinction previously existed. The results suggest that the trajectories are independent and that there was an initial absence of relative sex distinction. Other findings are that the transitions from absence to complex elaborated terminologies and the disruption of elaborate distinctions are very unusual.