Green-beard effects gained their name from a thought-experiment of Richard Dawkins (1976), who considered the possibility of a gene that caused its possessors to develop a green beard and to be nice to other green-bearded individuals. Since then, a 'green beard effect' has come to refer to forms of genetic self-recognition in which a gene in one individual might direct benefits to other individuals that possess the gene.
Such genes are essentially especially selfish, benefiting themselves regardless of the fates of their vehicles.
Note that because the green-beard effect depends on the ability of the individual to recognize the mirrored trait in other individuals, green-beard effects are most prevalent in organisms with sufficiently great intellects. Creatures of great intellect, such as humans, are capable of evolving culturally as well as genetically. Thus, insomuch as culture varies from our genes, the surface changeable adaptations of culture may magnify any underlying genetic green-bearding.
That explains Jewish-beard.
Who's got Ana-beard?