Brood parasitism is well summarized by Wikipedia:
the manipulation and use of host individuals either of the same (intraspecific brood-parasitism) or different species (inter-specific brood-parasitism) to raise the young of the brood-parasite. This relieves the parasitic parent from the investment of rearing young or building nests, enabling them to spend more time foraging, producing offspring etc.
As the orphanage statistics and the long recorded history of Gypsy breeding strategy indicate, the Gypsies have developed a human form of brood parasitism. If you adopt a Gypsy child, (for example one of the much-advertised “Romanian” orphans), besides probably doing less well in school due to lower IQ, they are likely to exhibit many of the behaviors of brood parasites, for example more sibling rivalry and less altruism and more selfishness towards both siblings and parents. Brood parasite theory also predicts that adopted Gypsy children are more likely to run away from home as teenagers than biological children. On the other hand, brood parasite theory predicts that Gypsy children while they are young are more adorable than your own biological children are or would be.
(Gypsies call themselves “Roma”, but “Gypsy” is the traditional term used by Europeans to refer to the racial group and their unique mobile lifestyle. Gypsies are no more Roman than they are Egyptian; in fact Gypsies migrated over a thousand years ago to Europe from the Indian subcontinent. Also the term “Roma” confuses them with their thoroughly white and Slavic Romanian neighbors.)
In our present culture, the brood parasite strategy of orphaning one’s children or giving them up for adoption has far more Darwinian fitness, i.e. it leads to more surviving children, than raising your own children. In this game Gypsies are far ahead as it seems to have been a common breeding strategy among them for many centuries if not millenia. It has evolved into genetic strategy, not just an ethnic quirk.
I am not the first to make the connection between Gypsies and other brood parasites. The cuckoo and its famously parasitical lifestyle is used as a metaphor for the “swarthy” (probably Gypsy) character Heathcliff in Emily Bronte’s fantasy of exotic genes, Wuthering Heights. If one has to delve into the dark corners of the female mind, this book is at least a refreshing change of pace from Jane Austen, Cinderella, and a million other fantasies about using the feminine charms to win commitment, power, and wealth from an alpha male. (Today these have reached the abysmal and preposterous depths of films like Pretty Woman, where a cheap hooker, representing the hundreds of millions of unpaid whores that now predominate among Western women, and who naturally adore this film, not only captures the wealth and status of an investment banker but changes him into a Good Person who will no longer practice the evil craft of finance, but will hereafter simply ladle out his ill-gotten gains to his “wife” the former hooker. Talk about parasites!) Although I must admit that Pride and Prejudice is well written and teaches quite a bit about women’s virtue that Pretty Woman fans have quite forgotten. But I digress. I had just intended to point out that Emily Bronte has a bit of priority in recognizing and looking at human brood parasitism.
Now back to the main topic. the brood parasite hypothesis predicts that Gypsy group cohesion is more a genetic than a cultural phenomenon. Brood parasites have very strong kin recognition that allows them to, when they “leave the nest” of their host parents, recognize, and selectively be altrustic towards and breed with, others who share their brood parasite genes. Group cohesion doesn’t require high IQ or a cultural ethic. Indeed, any merely cultural practice would be destroyed by the strategy itself. Adopted Gypsy children don’t learn any Gypsy culture until they grow up and run away to join the Gypsy circus, at which point it would be too late to inculcate any strong ethic. The epigenetic group cohesion that is essential to the brood parasite strategy must include, and only requires, an ability to recognize and be preferentially altruistic towards others who share those brood parasite genes.
Since Gypsies have, if the brood parasite hypothesis is correct, traditionally been dark-skinned brood parasites with light-skinned host parents, their ability to instinctively recognize and prefer each other’s company has been rather easy. Put them back in India, or put them in any area such as Silicon Valley with a large East Indian population, and the Gypsy-recognition signals might get mixed up, and they might end up culturally and genetically integrating with the East Indian population, despite the large IQ difference (especially in Silicon Valley!). That would be an interesting experiment.