For 25 years, the researchers have made detailed observations of bottlenose dolphins in the eastern gulf of Australia’s Shark Bay. That one-of-a-kind dataset allowed them to chart the relatedness of dolphin moms and map their habits of social association, then correlate these patterns to whether their offspring survived childhood.

As would be expected, calves born to moms from reproductively successful families tended to do well. But for dolphin moms from less-fit families, that lack of a pedigree was offset if they tended to hang out with successful moms. The researchers’ analysis suggested that keeping good company was just as important — even, at times, more important — than coming from good stock.