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By now, it’s relatively common for people conceived through sperm donation to discover half siblings floating around in the world who they’ve never met—people who, despite being strangers socially, share half their genetic material and perhaps even look, talk, or act like them. It’s a scenario that’s formed the basis for many a human-interest story and provided the backdrop for works of fiction, like the 2011 French comedy Starbuck (and its 2013 American remake, Delivery Man).

Of course, as sperm donation has grown more popular, the practices surrounding it have changed, too, trending ever more toward transparency: Today, parents of donor-conceived kids are far more likely to openly share their children’s origins with others than in the past, and more donors than ever before now opt to make their biographical details and contact information available to their donor offspring when they turn 18. In other words, sperm donation has become less of a family secret in the past few decades. In the new book Random Families, Rosanna Hertz and Margaret K. Nelson (sociologists from Wellesley and Middlebury, respectively) make the case that networks and family-like structures among genetically related donor offspring have evolved as a result.

Up until the 2010s, these networks—known colloquially as “donor-sibling networks,” and now often facilitated by social media—generally used to spring up when donor-conceived individuals discovered one another in their school-age, teenage, or adult years. Now, however, as Hertz and Nelson found in their study of recently developed donor-sibling networks, some parents are making contact with donor siblings or the parents of donor siblings as soon as their children are born or even conceived. These parents in particular have a unique vision for what the donor-sibling network could offer their kids later in life—they see it as something like a cross between an extended family and an alumni network.

In Random Families, Hertz and Nelson profile five donor-sibling networks. In the oldest network of the five, the participating donor siblings were in their mid-to-late 20s, conceived at a time when sperm donation was a quieter affair and most donors stayed anonymous forever. (This particular donor, an anomaly for his time, did not.) Three of the other groups are formed from donor siblings born in the 1990s and 2000s, and in the most recently formed network the book profiles, the 17 donor siblings were all born between 2011 and 2014. One feature that sets the last group apart is that the donor siblings’ participation isn’t voluntary, but rather is facilitated by their parents. (The authors refer to this group as the “social capitalists” for their emphasis on the social benefits the parents believe their kids stand to gain through participation.)

In some ways, this particular set of parents’ reasons for getting involved in a donor-sibling network look a lot like other people’s reasons: Many parents and donor-conceived kids want to identify and bond with genetic relatives out of a desire for emotional and practical support, and out of pure curiosity. The authors make clear that in every donor-sibling network they profiled, one primary reason for participation is a certain reasonable degree of fascination with the fact that kids raised by different families can have striking physical and even cognitive similarities. And that fact can help parents of genetically related kids support each other: When one child from the “social capitalists” network was diagnosed with childhood diabetes, for example, his parents notified the rest of the network via Facebook and received both messages of support and messages thanking them for giving the group a heads-up. Plus, Hertz and Nelson find, parents often feel a certain degree of affection for kids who are genetically related to their own, so a donor-sibling network can provide an additional source of goodwill and encouragement. As another parent from the group put it, “The more people out in the world who have a fondness for my kids and are fundamentally rooting for them in some ways, cheering them on, hoping the best for them—that’s not a bad thing.”

In other ways, the model that the latest parents of donor-conceived kids are creating is one that envisions donor siblings as a sort of underground network of social connections—one that could lead to advantages and opportunities that might otherwise be unavailable to them. As the parents in the “social capitalists” network look ahead to the future, according to the authors, “they are aware that the developing network may provide all sorts of social and cultural capital.” One parent interviewed by the authors compared the donor-sibling group to a group of alumni from a high-school organization that had a powerful influence on her when she was a teenager, and said that she imagined her son one day visiting Australia, where he is known to have donor siblings, and looking them up for a visit or to stay at their homes. Another parent in Boston imagines that perhaps one day her daughter will visit Chicago and be able to stay at the home of a donor sibling there, or that perhaps another donor sibling in California might help her other daughter get an internship somewhere. Another mom said, in a moment the authors describe as “frank,” that she hoped her daughter’s connections with her donor siblings would “deepen her Rolodex.”

Perhaps one way to understand this model of donor-sibling-network participation is as an extension of the distinctly 21st-century “helicopter parenting” phenomenon—these parents are, in a way, helicoptering at the earliest possible stage, acting on their children’s behalf to help them acquire the social lives and travel opportunities and careers their parents believe they deserve. Or, alternatively, faced with the troubling reality that young people today will likely be the first generation to be less successful than the generation before them, maybe these parents are simply using everything at their disposal to ensure that their children have chances to see the world and connections that can get them good jobs.

It is, of course, too early—for both outside observers and for these parents and donor-conceived kids themselves—to know whether this kind of involvement in donor-sibling networks will pay off in the ways envisioned. And perhaps it’s okay if it doesn’t. As the mother who imagined her child would one day crash with a donor sibling in Chicago admitted, “Maybe it means none of that concretely, maybe it just means that these people smile on [my daughters] and think kind thoughts and hope good things for them. I feel fine about that.”

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