Social support and subjective well-being of noncustodial grandparent caregivers in urban China: The mediating roles of generative acts

•Social support positively affected the subjective well-being of Chinese noncustodial grandparent caregivers.•Agentic generative acts mediated between social support and subjective well-being.•Older grandparent caregivers scored similarly with middle-aged counterparts in agentic generative acts and subjective well-being.