How effective are the different family policies for heritage language maintenance and transmission in Australia?

The one-parent-one-language (OPOL) approach has traditionally been considered a widely recommended strategy for heritage-language (HL) maintenance in bilingual families. However, alternative strategies, such as both parents consistently speaking the HL, may be equally or more effective. This study examines families’ self-reported language policies and their perceived effectiveness in HL maintenance in Australia, where minority languages often hold lower status than English and receive minimal institutional support beyond the home. Using data from a nationwide survey of 280 families, we analyzed parents’ self-reported language-use patterns and their perceived impact on HL transmission. Most mothers, who more often identified as primary caregivers, reported speaking a HL with their children, while secondary caregivers’ self-reported language use was varied. Families were categorized into four language-use approaches: OPOL, mixed-language use from one or both caregivers, HL-only from both caregivers, and single-caregiver only. Comparisons across these categories revealed that families following the HL-only and OPOL approaches reported significantly greater success in maintaining the HL than the other two groups, which showed no significant differences in self-reported outcomes. Follow-up analyses showed that Mixed-language families who reported high HL use percieved success comparable to that of HL-only and OPOL families. Our findings suggest that language input may be a central, but not exclusive, contributor to HL transmission. Families who reported higher perceived success showed strong commitment to HL maintenance, with caregivers likely reinforcing each other's efforts beyond direct language input. This study contributes to discussions on bilingual parenting and family language policy, providing empirical insights to inform HL maintenance strategies in diverse linguistic settings.